Grade 10Trigonometryprove the following cot2A.cot2B+cot2B.cot2C+cot2C.cot2A=1 aryan pokharl 8 Years agoGrade 10
Arun8 Years agoDear Aryan a + b + c = π; so (a + b) = π - c ==> cot(a + b) = cot(π - c) = -cot(c) ==> {cot(a)*cot(b) - 1}/{cot(a) + cot(b)} = -cot(c) Simplifying the above, cot(a)*cot(b) + cot(b)*cot(c) + cot(c)*cot(a) = 1 RegardsArun(askIITians forum expert)