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Solve cos x + cos 2x+...+ cos (nx) =n, n...

Solve `cos x + cos 2x+...+ cos (nx) =n, n in N`.

Text Solution

Verified by Experts

The correct Answer is:
`x=0`
We have `cos x + cos 2x +...+ cos (nx) =n`
Now, `cosx+cos 2x+...+ cos (nx) le n`
So, `cos x = cos 2x = ... = cos nx=1`
`:. x=0`
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