y = a(x - h)2(sqaured) + k

Question

Where would I put a number in order to stretch or compress the graph vertically in the equation above? And what does the a represent?

Answer 1

y = a(x-h)^2 + k

the value of "a" controls the vertical stretch or compression
if │a│ > 1 you have a stretch
if │a│ < 1 you have a compression

Answer 2

Thanks :D