How would you answer this?

Question

Recall that the quadratic function is the inverse of a square root function. What will we need to do in order to make this true, because the graphs do not look quite the same?

Answer 1

For each y value in the quadratic function, there are two real x values such that x² = y. For example, if y = 4, then x = 2 or x = -2.

However, mathematicians defined the square root as the positive root. Therefore, in the square root function, we omit the point (4, -2) and keep only the point (4, 2). As a result we only see the top half of the graph.

If we restrict the quadratic function to only x values greater than zero (causing us to omit (-2, 4)), the two functions will be inverses of each other.

Answer 2

Ddomain restrictions causing the problem...

Y=x^2 is the inverse of y= +and- sqrt(x)