Question

Find the inverse of the logarithmic function y =log₂(x + 7)

y = x2 - 7
y = x2 + 7
y = 2x2 + 7
y = 2x - 7
y = 2x + 7

Answer 1

1. Interchange x and y: x = log₂(y + 7)

2. Solve this resulting equatino for y:

x x

2 = y + 7 => y = 2 - 7

3. Replace "y" with

-1 -1 x

f (x): f (x) = 2 - 7 This is the desired inverse.

Answer 2

y=2x-7 answered off of a graphing calculator