f(x) = √x is the inverse function of f(x) = x^2, so it should look like a parabola on its side. However, because you can’t get a real number from the square root of a negative number, the half that is under the x-axis disappears like the blue graph in the image I’ve attached. Because you then add a negative after, the values become reflected over the x-axis, resulting in the red graph in the image.