Question

What is the inverse of the function f(x) = 2x + 1?

Answer 1

Explanation:

y = 2x + 1

x = 2y + 1

2y + 1 = x

2y = x - 1

y = x/2 - 1/2

f^-1(x) = x/2 - 1/2

Answer 2

f(x) = 2x + 1

Replace f(x) with y

y = 2x + 1

Switch x with y and y with x.

x = 2y + 1

Now solve for y. Subtract 1 from both sides.

x - 1 = 2y

Divide both sides by 2

(x - 1) / 2 = y

Replace y with f^-1(x)

f^-1(x) = (x - 1) / 2 is the inverse