mathematical induction to prove trig identity

[shallu]

Need urgent help to prove
cos^2(x)+cos^2(2x)+cos^2(3x)...cos^2(nx)=1/2[n+{cos(n+1)x}sin(nx)}/sin(x)] using mathematical induction.

 

[Deleted member 4993]

Need urgent help to prove
cos^2(x)+cos^2(2x)+cos^2(3x)...cos^2(nx)=1/2[n+{cos(n+1)x}sin(nx)}/sin(x)] using mathematical induction.

The first step of inductive proof is to show that the given equation is true for the lowest value of the parameter (here n = 1)

So start to show that at n=1, the given equation is an identity (true).

Please show us what you have tried and exactly where you are stuck.

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