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prove the following:
cotA×cotB+cotB×cotC+cotC×cotA=1

Prakash bhandari , 5 Years ago
Grade 10
anser 1 Answers
Aditya Gupta
this is true only if a+b+c= pi
proof: tan(a+b+c)=tanpi=0
(tana+tanb+tanc – tanatanbtanc)/(1 – tanatanb – tanbtanc – tanctana) = 0
or tana+tanb+tanc= tanatanbtanc
or 1/tanbtanc + 1/tanatanc + 1/tanatanb= 1
or cotA×cotB+cotB×cotC+cotC×cotA=1
KINDLY APPROVE :))
Last Activity: 5 Years ago
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