Does g(x)=2x^2 stretch vertically or horizontally?

Question

I can't tell if 2x^2 would be identified as (2x)^2 or 2(x)^2. There's no parentheses in the original problem although I assume that if it was (2x)^2 it would be indicated, but I just want to make sure. Thanks if you reply!!

Answer 1

It stretches vertically.  This is because you are increasing the y value by a scale factor of 2, but the x values remain the same.

 

x   |    x²     |         2x²

_____________________

 

0         0                 0

1         1                 2

2         4                 8

3         9                18

4         16              32