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Grade 11Trigonometry

IF A+B+C = 3 PIE / 2, THEN COS 2A + COS 2B + COS 2C IS

Profile image of laxman
11 Years agoGrade 11
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1 Answer

Profile image of Nishant Vora
11 Years ago
Hello student, Please find the answer to your question below

use the following formula for the first 2 terms,
CosC + CosD = 2Cos[(C+D)/2]Cos[(C-D)/2]
then cos 2c is cos (2pi – (2A + 2 B))

Now you can simplify and get the answer….….….….