f(x) vs (a)(f(x))
if a<0, that is known as a vertical compresion
our 1st 3 option show a vertical compression
since a<0, it will shrink vertically by a factor o 1/2
last option, hmm, range is height or y value
by subtracting 2, you move it in the x direction so no change in range from that
however, vertically compressing it makes the y values smallers so range is different
answer is only the 3rd option, shrink vertically
