Question

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

Answer 1

F(X) = 2x + 1

Replace f(x) with y:

Y = 2x+ 1

Switch variables:

X = 2y + 1

Solve for Y:

Subtract 1 from both sides:

X- 1 = 2y

Divide both sides by 2:

X-1 / 2 = y

Rewrite so y is in the left side:

Y = x-1 / 2

Replace y with f^-1(x):

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

This can also be written as x/2 - 1/2