Inverse Functions-Lesson 14JAN2013

Basically, an inverse function is the opposite of a function.

If you have a function, f(x) = 2x + 3 = y, the inverse function of this would be (y-3)/2.

f(x)   = 2x + 3 = y
   x    = (y - 3)/2 (make x the subject)
f-1(x) = (y-3)/2

To write the inverse function of f(x) = 2x + 3, write it this way: f-1(x) = (y-3)/2

*Special Rules*
• The inverse function of an inverse function is the original one.
• Not all functions can be inversed, e.g. f(x) = x^2 = y, which becomes x = ±√y. This is not a function as x has two values, one negative and one positive. (Remember that one of the requirements for functions is for the x value to have only one y value.)

Also, don't forget to comment under Polynomials - Revisions 1 & 2, division, and read through the introduction. :)

Done by Dylaine Ho (02)

No comments:

Post a Comment