Radicals - Day 3 (Wednesday)

Sorry for the delay in posts. I was having trouble connecting to the blogging site from work. And while I can email blogs in, I have not figured out how to get the images to appear correctly when I do. Here is Wednesday's lesson from last week:

Today we brought together the previous two lessons of radicals to make a connection between the graphs and solutions of equations. In a radical equation, the two sides of the equation can be graphed as separate functions. Then the solution to the equation is located at the x-coordinate of the intersection of the two graphs.

Example: Solve the following equation by graphing.

Step #1: Break up the equation into two functions, one for each side of the equation:

and

Step #2: Graph the two equations.

Step #3: Find the intersection. For this graph, the functions intersect at (9, 6).



Step #4: Find the solution. The solution is the x-coordinate of the intersection. For this equation, x = 9.

We extended this out to finding what is called the zeroes of the function. The zero of a function is the solution of the function equal to 0. When graphing g(x) = 0, we find that it is the x-axis. So, solutions of the equation equal to 0, and zeroes of a function, and x-intercepts of a graph are all the same thing!



Homework: Worksheet on Solving and Graphing Radical Equations

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