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Grade 11Trigonometry

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If A+B+C+D=2S,prove that

cos2S+cos2(S-A)+cos2(S-B)+cos2(S-C)=2+2cosAcosBcosC

Profile image of Subhajit Dhar
8 Years agoGrade 11
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2 Answers

Profile image of Saurabh Koranglekar
6 Years ago
Dear student

Please check the question

If you check values at s= 90, A = 45
Lhs=! Rhs

Regards

Profile image of Vikas TU
6 Years ago
Dear student 
Question is not clear 
Please attach an image, 
We will happy to  help you 
Good Luck
Cheers
 

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