Question

7. If A + B +C = 2S, then prove that cos(S - A)+cos(S-B)+cos(S-C)+cos S = 4 cosA/2 cosB/2 cos C/2
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Answer 1

Answer:

1-1L0 (hlo)

Step-by-step explanation:

If A + B +C = 2S, then prove that cos(S - A)+cos(S-B)+cos(S-C)+cos S = 4 cosA/2 cosB/2 cos C/2