# How do you graph y = 2 cos(2πx) ?

A general cosine graph of form $y = A \sin B x$ has amplitude A which represents the maximum displacement from the rest position, and period $T = \frac{2 \pi}{B}$ which represents the length on the x axis for 1 complete cycle.
So in this case $A = 2 \mathmr{and} T = \frac{2 \pi}{2 \pi} = 1$