How do you evaluate ##cos 3pi##?

| May 27, 2018

You can consider it visually as a graph and remember the periodicity of your ##cos##, meaning that it repeats itself at regular intervals (oscillating between ##+1## and ##-1##):
so that ##cos(3pi)=-1##

Get a 30 % discount on an order above $ 50
Use the following coupon code:
NEWYEAR
Order your paper today and get a 30% discountOrder Now
Positive SSL