Question

If you vertically stretch the linear parent function f(x)=x, by a factor of 2, what is the equation of the new function?

Answer 1

y=2x

Explanation:

The condition about stretching is that when the stretch factor is greater than 1, the function will be closer to OY axis; when the stretch factor is between 0 and 1, the function will be closer to OX axis.

We can observe this end result in the attached graphs.

The red line represent the original function and the blue line is y=2x

As we can observe that the condition still holds.