If n is an integer , prove that ,`cos(npi+theta)=(-1)^ncostheta`

If n is an integer, prove that, (i) cos(n pi + theta) = (-1)^(n) cos theta

If n is an integer then show that (1 + cos theta + i sin theta)^(n) + (1 + cos theta - i sin theta )^(n) = 2^(n+1) cos ^(n) ( theta//2) cos ((n theta)/2) .

If n is an integer and if sin theta=1, prove that theta=(4n+1)(pi)/(2)

If n is a positive integer,prove the following (1+cos theta+i sin theta)+(1+cos theta-i sin theta)^(n)=2^(n+1)cos^(n)((theta)/(2))cos((n theta)/(2))

If sin (pi cot theta)= cos (pi tan theta) and n is an integer, then prove that the value of cot 2 theta is of the form (1)/(4) +k .

If n is an integer and z=cos theta+i sin theta , then (z^(2 n)-1)/(z^(2 n)+1)=

For a positive integer n, let f_(n)(theta)=(2cos theta+1)(2cos theta-1)(2cos2 theta-1)(2cos(2^(2))theta-1)...(2cos(2^(n-1))theta-1) Which one of the following hold(s) good?

If n be a positive integer, then prove that (1+i)^n+(1-i)^n=2^(n/2+1)."cos"((npi)/4)

If theta = (pi)/(2 ^(n) +1) prove that 2 ^(n) cos theta cos 2 theta cos 2 ^(2) theta…. Cos 2 ^(n -1) theta =1

If theta = (pi)/(2 ^(n) +1) prove that 2 ^(n) cos theta cos 2 theta cos 2 ^(2) theta…. Cos 2 ^(n -1) theta =1