The graph of function g is a vertical stretch of the graph of function f by a factor of 3.

Which equation describes function g?

A. g (x) = 3f (x)

B. g (x) = f (3x)

C. g (x) = f (x3)

D. g (x) = 13f (x)

Question says that the graph of function g is a vertical stretch of the graph of function f by a factor of 3.

Now we have to find about which equation describes function g.

We know that if f (x) is the given function then a*f (x) gives vertical stretch or compress by a factor of a.

when 0
when a>1 then it stretches vertically by factor of a.

Given that function f is stretched by a factor of a so that means we use a=3 in formula a*f (x)

Hence final answer will be g (x) = 3f (x).

So choice A is correct answer.