The parent function is y = x²
The function y = 3x² vertically stretches the parent function, transforming the point (x, y) into (x, 3y)
For example, in the parent function you have the point (1, 1), then in the stretched function you will have the point (1, 3); in the parent function you have the point (2, 4), then in the stretched function you will have the point (2, 12); and so on.
