Wednesday, December 2, 2009
Geometric Justifications
Students will use these statements as reasons to justify their steps throughout this unit.
Homework: Page 219, #1 - 8; Page 221, #1 - 8
Last of the Triangle Inequalities
Monday, November 30, 2009
More Triangle Inequalities
The next theorem that we discussed is the Hinge Theorem (found in lesson 5.6). This theorem is applied to two triangles that have 2 sets of congruent sides. Whichever triangle has the longer of the two remaining sides must have an angle opened wider (the HINGE). We call that angle the "included angle" because it is between the two sets of sides that are congruent. This theorem was demonstrated for the students by using the hinge in the classroom door. As the hinge was opened for a wider angle, then the doorway had more open space across the opening.
Homework: Page 287, #4 - 12 even, #28; Page 289, #2 - 6 even, #18; Page 294, #2 - 10 even.
The next test will be on Thursday, December 10th. It will cover all Geometry topics taught through that date. There will be a review session Wednesday, December 9th, at 7:45 in my classroom (4303).
Remember, there are 6 help sessions offered to our IAA students each week:
Monday, 7:45am with Mrs. Bearden in 4210
Tuesday, 7:45am with Mr. Roth in P123
Tuesday, 3:30pm with Ms. Gonding in 4303
Wednesday, 7:45am with Mrs. Bearden in 4210
Thursday, 7:45 am, with Ms. Dufresne in 5207
Thursday, 3:30 pm, with Mrs. Martina in 5202
Tuesday
Wednesday, November 18, 2009
Review!
Homework: Study!
Monday, November 16, 2009
Polygon Angles
Example: A pentagon can be filled with 3 triangles:
Students discovered that there is relationship between the number of triangles it takes and the number of sides: There are always 2 fewer triangles to fill the shape than there are sides. Using this relationship, students can find the sum of the interior angles of any convex polygon by using the formula 180°(n - 2), where n is the number of sides.
Example: Find the sum of the interior angles of a 23-gon.
180° * 21 = 3780°
Example: There are 4 exterior angles shown in this quadrilateral.
Homework: Page 300, #2 - 24 even; Page 302, #2 - 14 even, #34.
There will be a quiz this week. It may be as early as Thursday. It will cover the lessons on angles (both interior and exterior) given on Friday, today, and tomorrow. There will be a review session Wednesday morning in room 4303 for this quiz.
Remember: Vocabulary definitions are due on Wednesday!
Remember, also: The Logic Project is due on Friday!
Friday's lesson ...
The class also learned that an exterior angle (an angle formed by extending a side of a triangle beyond the triangle) has a measure equal to the sum of the two non-adjacent (meaning "not next to") interior angles. If the students are given a problem with an expression for an exterior angle of a triangle, they should add together the measures of the two angles that do not touch the exterior angle and set that equal to the measure of the exterior angle. Then they should solve that equation.
Homework: Triangle Angle Worksheet
Thursday, November 12, 2009
Logic Statements
The conditional statement has the "if - then" format. The "condition to be met" is called the hypothesis and follows "if". The "result" is called the conclusion and follows "then"
Example: If all students are present on the day of a quiz, then they will get 2 bonus points. (This is true for my classes.)
The converse switches the hypothesis and the conclusion.
Example: If all students get 2 bonus points, then they were all present on the day of a quiz. (This could be true, but it could be false if they all did a bonus problem correctly and that is why they got the bonus points. This is called a counterexample, it is an example that counters the argument.)
The inverse is formed by negating both the hypothesis and the conclusion of the original conditional statement.
Example: If all students are not present on the day of a quiz, then they will not get 2 bonus points. (Again, this may not be true if they still answer the bonus question for the extra points.)
The contrapositive is formed by switching and negating both the hypothesis and conclusion of the original conditional (this is a combination of the converse and the inverse).
Example: If all students did not get 2 bonus points, then they were not all present on the day of a quiz. (This is true for my classes.)
The second day of this lesson brings in the final logic statement. The biconditional statement is formed with both the conditional statement and the converse are true. It is not written in "if - then" form. Instead, this statement places "if and only if" in the middle of the hypothesis and conclusion (sometimes abbreviated "iff"). Definitions are often written in the biconditional format in our class.
Example: An angle is a right angle if and only if it measures 90 degrees (the definition of right angle).
Homework: Yesterday's - Page 207, #1 - 10 and Page 209, #1 - 8. Today's - Page 207, #11 - 19 and Page 209, #17 - 19.
Students were also given a project today. This project is called "The Logic of Advertising". Individually, or in pairs, the students must find 3 slogans to convert to conditional statements and then write the converse, inverse, and contrapositive. All 12 sentences (4 sentences for each of 3 ads) must be typed and clearly identified on a single sheet of paper. Then, a presentation can be made (power point, poster, video) to share the sentences with the class. This project is due on Friday, November 20th.
Tuesday, November 10, 2009
A New Unit!
Today's introduction to geometry had absolutely NOTHING to do with shapes. The classes were told that math isn't about numbers and shapes. Math is about the logic and rules that show we can work with numbers and shapes and their relationships. So, our handouts were about logic. There are two types of logic: Deductive Reasoning and Inductive Reasoning. Deductive reasoning uses rules, definitions, laws, and properties to make a logical argument (think of the television shows like CSI, NCSI, or NUMB3RS). Inductive Reasoning looks at patterns and draws a conclusion from them (think of shows like Criminal Minds or Lie To Me). We did two riddle-type logic questions and then looked at a larger logic problem that uses a grid to organize the information and answers. Students are to finish the logic problem for homework.
Also, the unit 3 vocabulary was passed out today. Students are to definite the 27 terms by next Wednesday, November 18th.
Tuesday, November 3, 2009
Rational Expressions: Adding & Subtracting
Example:
However, if the fractions do not already have a least common denominator, then the LCD must be made. To do this,
- Factor the denominators.
- Multiply each denominator by what the other denominator has but it doesn't already have.
- Remember, whatever you multiply by on the bottom of a fraction, you must also multiply by in the top of a fraction.
Example:
Homework: Page 173, #1 - 10, 13 - 17, 20; Page 174, #1 - 3It was very nice to see so many students take advantage of today's help sessions. Remember, every Tuesday and Thursday morning & afternoon there is an IAA teacher willing to work with our IAA students!!
The test will be on Friday covering square roots, polynomials, factoring, and rationals. Students will receive a thorough review sheet tomorrow. There is a review session Thursday morning at 7:45 am, in room 4303.
Monday, November 2, 2009
Rational Expressions: Multiplying & Dividing
To Multiply Rational Expressions:
- Write each expression as a fraction.
- Factor each expression. Remember, GCF first. Then try to factor a quadratic polynomial.
- Cancel common factors either vertically or diagonally. But NOT horizontally.
- Multiply the remaining expressions by multiplying "straight across". Numerator times numerator. Denominator times denominator.
To Divide Rational Expressions:
- Write each expression as a fraction.
- Change to a multiplication problem by flipping the second fraction over (reciprocal!). Many students know this step as "KFC" for Keep, Flip, Change.
- (Now follow multiplication steps.) Factor each expression
- Cancel common factors vertically or diagonally.
- Multiply the remaining expressions straight across.
Homework: Page 167, #2 - 8 even, #10 - 17 all; Page 168, #2, 4, 8, 10, and 14
Extra Help: The IAA teachers are offering extra help for 30 minutes Tuesdays and Thursdays, before and after school. Students can attend any session, no matter who their teacher is.Tuesday, 7:45 am, with Mr. Roth in P-123
Tuesday, 3:30 pm, with me, in room 4303
Thursday, 7:45 am, with Ms. Dufresne in room 5207
Thursday, 3:30 pm, with Mrs. Martina in room 5202
Also, if students need more practice with a lesson they can try Purple Math.com or the textbook website for additional tutorials & practice.
Friday, October 30, 2009
Rational Expressions: Excluded Values & Simplifying
Today, we worked with rational expressions. Rational expressions are expressions that can be written as a fraction. However, even when the fraction is made with polynomials, we have to remember that the denominator cannot equal 0. So, we have to list any exclude values.
Example: Find the excluded values from the following rational expression.
- Set the denominator equal to zero: 25u2 - 36 = 0
- Solve the equation to find the excluded values. Look back at Tuesday's notes to remember how to solve by factoring.
We also discussed how to simplify rational expressions. This concept was taught last Friday, so today's lesson reviewed and reinforced that previous understanding.
Homework: Page 163, #2 - 14 even and #19; Page 164, #3 - 8 and #11 - 13
There will be a test next Friday covering ALL of unit 2: Radicals, Polynomials, Factoring, & Rationals.
Wednesday, October 28, 2009
Applications & Review
Homework: Review worksheet for tomorrow's quiz.
There is a review session tomorrow morning in room 4303. The students should bring their completed review worksheet.
Tuesday, October 27, 2009
Solving by Factoring
- Set the equation equal to zero.
- Completely factor the polynomial expression.
- Set each factor equal to zero and solve the equations.
Here, we find out that there are 4 vocabulary terms that are very similar in use/definition: solutions, roots, zeros, and x-intercepts. The methods are almost the exact same for finding any one of those terms. However, when we are presented with a function in function notation, step 1 - Set equal to zero simply becomes rewrite f(x) as 0.
Monday's Notes ...
Monday's lesson went over the last two types of factoring that we will use this semester.
Differences of two squares: This type of quadratic polynomial has two perfect square terms that are being subtracted. The factors of this type look like the conjugates that we have seen several times in the last month and a half. To make the middle (linear) term of the quadratic drop out, the factors must have had the exact same terms, but opposite signs.
- Create groups of the terms in such a way that each grouping has a gcf.
- From each group, factor out the gcf.
- The remaining factors in the parenthesis must be the same to continue. Now that the parenthesis have the exact same terms, that is a gcf of both parts of our polynomial expression. Factor the parenthesis out to the front and create another parenthesis with what is left behind.
Students saw a similar problem to Step 3 in notes from last Wednesday: Factoring by Using a Greatest Common Factor, example "l".
Homework: Finish the Handout
Remember - there will be a quiz on Thursday covering all uses of Factoring! There will also be a binomial expansion problem (from last Monday). We will have a review session Thursday morning at 7:45 am in room 4303 to prepare for this quiz.
Friday, October 23, 2009
Bringing it together ...
- Remember, it may be helpful to rewrite a division problem as a fraction. To do this, the dividend (what is being divided into) goes in the numerator. The divisor (what is doing the dividing) goes in the denominator.
- Factor the polynomials. First, look for a gcf. If there is one, pull it to the front. Then, if the polynomial is a quadratic, factor it like yesterday's lesson.
- Cancel any common factors that appear in both the numerator and the denominator.
- Write the simplified answer.
Thursday, October 22, 2009
Factoring Quadratic Trinomials
Example: Factor x2 + 5x - 36
- Consider factors of the constant term (c, or the last term). Here: -36 is -1*36; -2*18; -3*12; -4*9; -6*6; -9*4; -12*3; -18*2; -36*1.
- Choose the pair of factors whose sum is the coefficient of the linear term (b, or the middle term). Here: -4 + 9 = 5
- Create your factors (2 sets of parenthesis) by filling in the variable and the factors chosen in step 2. Here: (x - 4) (x + 9)
The two numbers needed to complete the puzzle are -9 and 4, as shown below.
Homework: Page 83: #1 - 9; Page 84: #1 - 6; Page 91: #1, 7, and 13
Wednesday's Notes ...
Example: Factor 9a3 + 12a2 - 15a
- Look at each number and identify the largest number that can go into each evenly. Here, 3 goes into 9, 12, and -15 evenly.
- Look at each variable and identify how many each term has in common with the others. The students were told to find the smallest exponent because that term limits how many the others can have in common. Here, each term has one a-variable. While the first and second terms have more a-variables, the last term only has one so it limits the common factor.
- Write the GCF and then start parenthesis after that: 3a ( ______ )
- To find what polynomial goes inside the parenthesis, determine term by term either "what is left when we divide by the gcf" or "what multiplies with the gcf to make the term". Here, 3a * 3a2 makes the first term of 9a3. 3a * 4a makes 12a2. And, 3a * -5 makes -15a. So, the final answer after factoring out the gcf is 3a (3a2 + 4a - 5).
- We can check every factoring problem by multiplying the factors back together. Their product should be the original polynomial. Remember, add exponents when multiplying bases. Here: 3a * 3a2 + 3a * 4a + 3a * -5 = 9a3 + 12a2 - 15a.
Homework: Page 79: #13 - 21 and Page 80: #10 - 18
There will be a quiz on Thursday, October 29 on factoring and solving by factoring (for the next week).
Tuesday, October 20, 2009
Grades ...
Students received a grade print out with all of their grades. Most of these progress reports also have notes on them about the EOCT Practice Test and the quiz replacement. These papers need to be signed by the parents and returned to school.
Notice: We were going to have a test on Thursday. That test is cancelled. We will move on to the concept of factoring polynomials tomorrow. More information to come soon!
Homework: Square Root and Polynomial Review Worksheet
Notes from Monday ...
Example: Simplify (x + y)4
This problem would require us to multiply out (x + y)*(x + y)*(x + y)*(x + y). The students saw through a problem in class that this is a lengthy process with many places to have errors. The Binomial Theorem and Pascal's Triangle makes this much simpler.
- Note the exponent and go to that row of Pascal's Triangle. Here, the exponent is 4 so we will use row 4: 1, 4, 6, 4, 1. These numbers become our coefficients (numbers in front of the variables). We write the numbers down followed by 2 blanks each: 1_ _ 4 _ _ 6 _ _ 4 _ _ 1_ _
- To start filling in the blanks, use the first term inside the parenthesis (here, x). This term will start with the exponent of the problem (here, 4) and then count down as it fills in the blanks from left to right: 1 x4 _ 4 x3 _ 6 x2 _ 4 x1 _ 1 x0 _
- To finish filling in the blanks, use the second term inside the parenthesis (here, y). This term starts with the exponent of 0 and counts up to the exponent of the problem as it fills in the blanks from left to right: 1 x4 y0 4 x3 y1 6 x2 y2 4 x1 y3 1 x0 y4 . Notice that each term has exponents that add together to 4 (the exponent in the problem).
- Simplify, if possible. Remember, any non-zero value raised to the 0 power is 1, so we remove that from our answer. If there are any numbers raised to powers, this is the step to simplify those powers and multiply times the coefficients. Here: 1 x4 4 x3 y1 6 x2 y2 4 x1 y3 1 y4
- Enter the signs throughout the polynomial answer. If the binomial has addition, then all signs in the answer are plus signs. If the binomial has subtraction, then all signs alternate plus and minus, with the first term being positive. Here: 1 x4 + 4 x3 y1 + 6 x2 y2 + 4 x1 y3 + 1 y4
Homework: Page 75, #2 - 16 even and #24
Tuesday, October 13, 2009
Quiz #4
Students will not have math class tomorrow. Instead they will take the PSAT in their homerooms. I will be out Thursday and Friday of this week at a math teacher conference. Thursday, students will have a guide to working with polynomial division. Friday, students will take a practice EOCT. This practice test will be in a multiple choice format. It will be cummulative with problems from the last 9 weeks. This practice test cannot hurt a student's average. However, it may be used to raise a grade.
Monday, October 12, 2009
Quiz #4 Review
There will also be a review session tomorrow morning at 7:45 in my classroom (4303).
Thursday, October 8, 2009
Multiplying Polynomials
Example: 4x2y * -6x3y2
- Multiply the coeffiecients together: 4 * -6 = -24
- Multiply the variables together by adding exponents: x2 * x3 = x5 and y * y2 = y3
- Write the product: -24x5y3
We also practiced multiplying polynomials. See yesterday's blog for examples of the tiles and Punnet square methods. FOILing and distributing requires us to multiply each term in the first polynomial times each term in the second polynomial. Finish by collecting like terms. Remember, do not change the exponents when collecting like terms (adding/subtracting). [FOILing stands for First, Outer, Inner, and Last. Those are the pairs of terms based on location to multiply. It ONLY works when multiplying a binomial (2 terms) times another binomial (2 terms) such as (4x + 2) (5x - 8).]
Example: (4x + 3) (5x2 - 2x + 10)
= 4x (5x2) + 4x (-2x) + 4x (10) + 3 (5x2) + 3 (-2x) + 3 (10)
= 20x3 - 8x2 + 40x + 15x2 - 6x + 30
= 20x3 + 7x2 + 34x + 30
Homework: Page 67: #2 - 20 even AND Page 71: #2 - 18 even
Remember, there will be a quiz next Tuesday covering this week's lessons.
Enjoy your 3 day weekend from school!!!
Wednesday, October 7, 2009
Multiplying with tiles
Example: Find the product of (x - 3) * (x + 2).
- Set up the dimensions to the side of the work space (as shown above and to the left of the diagram below).
- Fill in the space with shapes matching the dimensions. Or, continue the lines down and across that are started in the dimensions.
- Record the values of the shapes in the resulting rectangle as the product. Simplify zero pairs.
We also found the product of the two polynomials by using a chart that is similar to the Punnett squares that the students learned in Biology in middle school (and will see again this year).
Example: Find the product of (x + 2) * (x2 + 3x + 1)
- This process again requires the students to set up the polynomials on the top and side of the work space (this time as collected terms rather than individual tiles).
- Each box in the grid is found by multiplying the term above and to the left.
- Collect like terms for the answer (usually on diagonals).
We will continue working with this concept tomorrow. There is a quiz scheduled for Tuesday covering adding, subtracting, and multiplying polynomials.
Homework: Finish today's packet
Tuesday, October 6, 2009
Adding & Subtracting Polynomials
Examples:
(4x2 + 5x - 8) + (2x2 - 3x - 4)
= 6x2 + 2x - 12
(9x2 - 2x - 5) - (7x2 - 6x + 4)
= (9x2 - 2x - 5) + (-7x2 + 6x - 4)
= 2x2 + 4x - 9
Homework: Page 61: #1 - 14 and Page 62: #14 - 19
Monday, October 5, 2009
Catch up post! (Sorry!)
Friday, we had a quiz covering square roots. There was no homework.
Today (Monday), we used colored tiles called Algebra Tiles to learn the processes of adding and subtracting polynomials.
For adding polynomials:
- Group/Collect like terms - the terms that have the same variable(s) to the same exponent
- Add the coefficients, keep the term like what they started as - same variable(s) to the same exponent
- Write the resulting polynomial
For subtracting polynomials (KFC or "add the opposite"):
- Keep the first polynomial the same
- Flip the signs of the second polynomial (positive to negative, and vice versa)
- Change the problem to addition
- Follow the steps for addition
Homework: finish today's packet. Students could checkout a packet of Algebra Tiles from me. They may use the tiles on next week's quiz (but they do not have to use them).
Quiz: Next Tuesday, October 13th covering adding, subtracting, and multiplying polynomials.
Wednesday, September 30, 2009
Solving Quadratics by Square Rooting
Homework: page 121 #2 - 26 even (not #20) and page 122 #1 - 6
Reminder: The quiz will be Friday. There is a review session available Friday before school in room 4303.
Tuesday, September 29, 2009
Reviewing square roots
Homework: Finish worksheet "Lesson 3.4 Practice" and Unit 2 Vocabulary
Monday, September 28, 2009
Dividing with square roots
- Simplify any radicals with perfect squares
- Reduce the fraction, if possible ... check again for perfect squares
- Rationalize the Denominator - this is a process of eliminating square roots from the denominator of a fraction. This can take two forms. One form has us multiply the top & bottom of the fraction by a radical that will make the denominator into a perfect square. The other form has us multiply the top & bottom of the fraction by the conjugate of the denominator. Conjugates are specially made to eliminate square roots when they are multipied together. Conjugates have the same numbers & radicals, but they have opposite signs in the middle.
Examples of conjugates: (4 + √3) and (4 - √3); also (6 - √10) and (6 + √10)
For more help rationalizing denominators, try http://www.purplemath.com/modules/radicals5.htm
In fact, all of the lessons at Purple Math are well written with several examples.
There will be a quiz on Wednesday. We will hold a review session Wednesday morning at 7;45 in room 4303 for that quiz.
Homework: page 144 #10 - 18 & page 145 #8 - 15
Friday, September 25, 2009
Square Roots
Homework:
Due next Thursday - Unit 2 vocabulary definitions
Due Monday - Page 144: #1 - 9, #19 - 24 and page 145: #1 - 7, #16 - 20
There is a quiz scheduled for next Wednesday that will assess the students' understanding of simplifying square roots and using square roots to solve quadratic equations (lessons from today through Tuesday).
Thursday, September 24, 2009
TEST
A few students needed the full classtime to complete the test. But, most students finished with enough time left in the period to start their homework assignment.
Homework: "Why Did Krok ..." worksheet with problems on simplifying square roots. These problems are review problems. Students must show work for each problem to get full credit tomorrow. Just a reminder: break up the number under the square root sign to find factors that are perfect squares so that they can be square rooted.
Example: √75 = √25 * √3 = 5 √3
Wednesday, September 23, 2009
Review
Homework: STUDY!!!
Tuesday, September 22, 2009
No school!
The review session that was originally planned for today will now happen tomorrow morning, 7:45 am, in room 4303. We will push the test off to Thursday.
Monday, September 21, 2009
Rainy Monday Review
Reminder: tomorrow morning, review session, at 7:45 am, in room 4303
Friday, September 18, 2009
Sequence formulas
- a1 = 5 ← This is the starting or first term
- an = an-1 + 3 ← This is the what the sequence does, it adds 3 to the previous term.
This can also be done with an explicit formula which defines each new term in the sequence based on its position. For example, the explicit formula for 5, 8, 11, 14, ... is:
- First, we recognize that there is a rate of change of 3 for the terms in the sequence. This becomes the slope for the formula. We will start with an = 3n
- But, when we substitute n = 1 to find the first term, 3 * 1 = 3. This is 2 units short of the first term. We will add 2 to our formula to bring the output values up to the sequence terms.
- an = 3n + 2
Homework: Complete the handout with Sequences: Part 5 and Sequences Homework on the front and back. We will spend Monday reviewing all of the sequences concepts. We have a test scheduled for Wednesday. There will be a review session in the morning, Tuesday the 22nd, at 7:45 in room 4303.
Have a great weekend!
Thursday, September 17, 2009
Sequences, day 1
Homework is ...
page 185: #1 - 3
page 187: #2 - 18 even
page 188: #2 - 16 even
We will have a test on Wednesday, September 23rd covering Transformations, Rates of Change, and Sequences. There will be a review session on Tuesday, September 22nd at 7:45 in room 4303. We will also review in class
Wednesday, September 16, 2009
Recovery information
For the test on Unit 1 Part 1, the students must have earned 35 out of 39 points on the assingments. To do recovery on this test, they need to schedule time with me either before or after school to rework the problems that they missed. Recovery must be done by next Wednesday, September 23rd.
Recovery is not available for quizzes. However, there will be other opportunities later in the semester to improve quiz grades.
There is no homework for math today!
Tuesday, September 15, 2009
More Average Rates of Change
Homework is in the textbook. Page 183: #1 - 7. Page 184: #1 - 6
Remember, tomorrow is an Early Release Day. Tests and Quizzes will be returned along with going over the homework.
Monday, September 14, 2009
"Walking, Falling ..."
We went over "Walking ..." from last Wednesday. This handout introduced the concepts of rate of change and average rate of change. We investigated how Dwain's speed remained constant at 4 feet per second, while Bryan's speed changed each of the first 5 seconds. However, they both ended their race in a tie.
We ended class by starting "... Falling ..." Remember, although there is a constant change to the speed of the falling ball, it is still a changing speed. It has a constant increase or acceleration of 9.4 (this is the acceleration due to gravity on Earth). The formula to calculate the average rate of change is:
Friday, September 11, 2009
Quiz Day!!!
Remember to bring "Walking ... Part 1" to class with you on Monday. You were assigned to finish the handout on Wednesday. We will go over that and continue discussing Rates of Change next week.
Have a great weekend!