Question

Consider the function f(x) = x2 and the function g(x) = 3x2. How will the graph of g(x) differ from the graph of f(x)?

Select the correct answer

The graph of g(x) is the graph of f(x) shifted to the left 3 units.

The graph of g(x) is the graph of f(x) stretched vertically by a factor of 3.

The graph of g(x) is the graph of f(x) compressed vertically by a factor of

The graph of g(x) is the graph of f(x) shifted up 3 units. ​

Answer 1

Third Choice - The graph of g(x) is the graph of f(x) compressed vertically by a factor of 3

Explanation:

x^2 is the the parent function, so it opens up with a normal compression.

Any number > (greater than) 1 as a coefficient of x will lead to a vertical compression (narrower parabola), while any number < (less than) 1 as a coefficient of x will lead to a vertical stretch (wider parabola).

So, 3x^2 would have to have to be a compressed parabola.

I hope this helps!

Answer 2

The graph of g(x) is the graph of f(x) stretched vertically by a factor of 3.

Explanation:

A vertical stretch or shrink of a function, kf(x), results from multiplying the entire function by a constant, k.

In this case, g(x) equals 3 times f(x). If k > 1, then the graph will be stretched vertically (along the direction of the y-axis) by a factor of k.

So, the graph of g(x) is the graph of f(x) stretched vertically by a factor of 3.