# How do you graph y=2cos2x?

Apr 19, 2015

You can deduce a lot of things from the equation representing your function.

It is a cosine with amplitude of $2$ and a length $\lambda$ (before it repeats itself) that can be found using the $2$ in front of $x$ as the value of $k$ in:

$k = \frac{2 \pi}{\lambda}$

giving: $\lambda = \pi$ basically it is a squashed cosine function that instead of going from $0$ to $2 \pi$ goes from $0$ to $\pi$: