SOLUTION: My homework tells me to prove an identity, sin(x-3 times pie divided by 2)=cosx I cant figure it out please help

Question 88275: My homework tells me to prove an identity, sin(x-3 times pie divided by 2)=cosx
I cant figure it out please help
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!

Use the trig identity

Evaluate to get -1

Evaluate to get 0

Multiply. So the identity has been proven

As always we can graph the two expressions (the given and the result) to see if they are equivalent.
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