Question

Find the inverse of the square root function $f$.
$f\left(x\right)=\sqrt{x-1}$

• A. $x^2-1$
• B. $x^2+1$
• C. $x+1$
• D. $x-1$

Answer 1

The correct option is B $x^2+1$

Let $y=f\left(x\right)=\sqrt{x-1}$ and now solve for $x$ to find the inverse of the given function.

$y=\sqrt{x-1}$, squaring both sides we get,

$y^2=x-1$

$x=y^2+1$

Therefore, the inverse of the function in terms of $x$ is $x^2+1$.