How do you find the inverse of $f (x) = \sqrt{2 x + 5}$ $f(x)=sqrt(2x+5)$ ?

Question

3542 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-11-09T10:29:41

$f'(x)=(x^2-5)/2$

$y=sqrt(2x+5)$

First, we switch the $x$ s and $y$ s to get $x=sqrt(2y+5)$

Now, we must rearrange to make $y$ the subject:
$x^2=(sqrt(2y+5))^2=2y+5$
$x^2-5=2y$
$y=(x^2-5)/2$

How do you find the inverse of f(x)=sqrt(2x+5)f(x)=√2x+5f(x)=sqrt(2x+5)?