Question: what is the difference between horizontal and vertical stretch?
Answer: A vertical compression (or shrinking) is the squeezing of the graph toward the x-axis. if k > 1, the graph of y = k•f (x) is the graph of f (x) vertically stretched by multiplying each of its y-coordinates by k. ... if k should be negative, the horizontal stretch or shrink is followed by a reflection in the y-axis.