For f(x) = a(x - h) squared + k, what does a size of a above 1 do to the graph?

1. The number a in front of the squared bracket controls a vertical stretch. 2. A size above 1 pulls every point further from the horizontal axis. 3. So the parabola looks narrower, while a size below 1 makes it look wider. _Source: OpenStax Precalculus (CC BY 4.0), section 3.2 Quadratic Functions_