Question

The graph of function gis the graph of function f (x) = 2x2 + 5 after a

vertical stretch by a factor of 3. What is the function rule for function g?

Answer 1

Answer: g(x) = 6*x^2 + 15

Explanation:

Suppose that we have a function y = f(x)

A vertical stretch by a factor of K is written as:

g(x) = K*f(x).

In this case, we have f(x) = 2*x^2 + 5.

And we know that g(x) is a f(x) after a stretch by a factor of 3.

Then we get:

g(x) = 3*f(x) = 3*(2*x^2 + 5) = 3*2*x^2 + 3*5 = 6*x^2 + 15

g(x) = 6*x^2 + 15