SAT Subject Test Mathematics Level 2

Here’s what you do to find the inverse of a function. First, put y in the place of f(x) to make a more
familiar-looking equation form:

Second, solve the equation for x in terms of y:

INVERSE FUNCTIONS

Third, put f−1(x) in the place of x and put x in the place of y:

(D) 3 x −3

(E) 3 x −9

To  find    the inverse of  a   function:

1. Replace  f(x)    with    y.

2. Solve    the equation    for x   in  terms   of  y.

3. Replace  x   with    f−1(x)  and replace y   with    x.

Graphs  of  inverse functions   are symmetric   about   the line    y   =   x.

The slopes  of  the lines   of  inverse functions   are reciprocals.