The function returns a number y such that y2=x: f(x)=√x≡x12.
The graph of the square root function looks like this:
{{ :math:sqrt_of_x.jpg?500 |The graph of the function √x.}}
y2 is negative, the function f(x)=√x
is not defined for negative inputs $x$.
you can have nth root n√x which is the inverse
function to $x^n$. For example, the inverse function for the cubic function $f(x)=x^3$ is the //cube root//: \[ f(x) = \sqrt[3]{x} \equiv x^{\frac{1}{3}}. \] So we have $\sqrt[3]{8}=2$ since $2\times2\times2=8$.