Question

Suppose the point (5,-1) is on the graph of y=f(x). Find a point on the graph of function y=3f(x)

Answer 1

You are applying a vertical stretch by a factor of 3 to the original function, y=f(x).

y=3f(x) is the new function with a vertical stretch of 3 applied to it.

Therefore, just multiply the y coordinates by 3 to get you new point

(5,-1)-->(5,-3)