Question

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

Answer 1

Answer:

$\displaystyle f^{-1}(x)= \frac{1}{2}x - \frac{1}{2}$

Step-by-step explanation:

f(x) = 2x + 1

f(x) = y (output)

y = 2x + 1

Solve for x.

y - 1 = 2x

Divide 2 on both sides.

y/2 - 1/2 = x

1/2y - 1/2 = x

Switch variables.

1/2x - 1/2 = y

$f^{-1}(x)= \frac{1}{2}x - \frac{1}{2}$

Answer 2

Answer:

$f^{-1} = \frac{x-1}{2}$

Step-by-step explanation:

$f(x) = 2x+1$

Replace it with y

$y = 2x+1$

Exchange the values of  x and y

$x = 2y+1$

Solve for y

$x = 2y+1$

Subtracting 1 from both sides

$2y = x-1$

Dividing both sides by 2

$y = \frac{x-1}{2}$

Replace it by $f^{-1}$

So,

$f^{-1} = \frac{x-1}{2}$