Question

Find the inverse of the function.

y = –3 over x + 4

A. x = 4y – 3 over y
B. y = 4x over 3
C. y = x –3 over x
D. y = –4x –3 over x

Answer 1

`y= (-3)/(x+4)`

Step 1: Isolating x on one side of the equation.


`y(x+4)=-3 \\ \\ x+4= (-3)/(y) \\ \\ x= (-3)/(y)-4`

Step 2: Replace x by f'(y)


`f'(y)= (-3)/(y)-4`

Step 3: Replace each occurrence of y by x


`f'(x)= (-3)/(x)-4 \\ \\ f'(x)= (-3-4x)/(x)`

Thus, option D gives the correct inverse of the given function