SOLUTION: cos beta=0.4, find the value of cos beta +cos(beta+2pi)+cos(beta+4pi)

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Question 1022246: cos beta=0.4, find the value of cos beta +cos(beta+2pi)+cos(beta+4pi)
Answer by ikleyn(52834) About Me  (Show Source):
You can put this solution on YOUR website!
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cos beta=0.4, find the value of cos beta +cos(beta+2pi)+cos(beta+4pi)
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cos%28beta+%2B+2%2Api%29 = cos%28beta%29;

cos%28beta%2B4%2Api%29 = cos%28beta%29.

Therefore

cos%28beta%29 + cos%28beta%2B2pi%29 + cos%28beta%2B4pi%29 = 3%2Acos%28beta%29.