Hi I'm new to this, I've been given a question on compound angles and I really don't know how to go about it. Any help would be greatly appreciated:

Using compound angles prove that Cos(y-pi)+Sin(y+pi/2)=0

thanks Shaun

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- Feb 14th 2013, 04:33 PMKosky1Compound angles HELP!
Hi I'm new to this, I've been given a question on compound angles and I really don't know how to go about it. Any help would be greatly appreciated:

Using compound angles prove that Cos(y-pi)+Sin(y+pi/2)=0

thanks Shaun - Feb 14th 2013, 05:25 PMSorobanRe: Compound angles HELP!
Hello, Shaun!

You are expected to know these Compound Angle Identities:

. .

. .

Quote:

Using compound angles prove that: .

We have: .

. . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . .

We have: .

. . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . .

Therefore: .

- Feb 14th 2013, 05:47 PMKosky1Re: Compound angles HELP!
Ah thankyou. I had those identities right infront of me! Had a complete mind block

Thank you ever so much!