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Trigonometry> prove that cos35+cos85+cos155=0. plz sir/...

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prove that cos35+cos85+cos155=0.

plz sir/madam give me the full solution

Thank you

Chinnu , 5 Years ago

Grade 11

1 Answers

Vikas TU

Last Activity: 5 Years ago

Dear student

Cos35 +cos85+cos 155
Cos(60-25)+cos(60+25)+cos155
2 cos60 cos 25 + cos (180-25)
2*1/2 cos25 - cos 25
Cos 25 - cos25=0

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