Sunday, January 23, 2011

Inverses Chapter 4

This week we continued Chapter 4. We were introduced to inverse functions in Section 5. This chapter was fairly simple being the only thing you had to do is switch the x’s and y’s in the equation and then simply solve for y. For this section there weren't many steps to the process but before you did anything to the function you must graph the equation on a coordinate plane. Once you have the equation graphed you use a method called the horizontal line test and test the function. If it passes and is an inverse you can move alont the rest of the process.

How to do a horizontal line test: 1.draw horizontal lines across the graph.
2. if it doesn't touch more than one point you can find the inverse.
* Note that in college we will be taught differently and they'll show you a way to find the inverse even if it fails the test.

To show something is an inverse be sure to put the -1 exponent after the y once you have solved the equation.

Example:Find the inverse for y = x -9
You graph this equation, and do the horizontal line test, and it does pass.
1. Switch the x and y. x= y-9
2. Solve for y. y = x + 9
3. Y^-1 = x + 9

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