`cos 2 theta ` is not equal to

cos2theta is not equal to

If cos alpha + cos beta = a, sin alpha + sin beta = b and theta is the arithmetic mean between alpha and beta then sin 2 theta + cos 2 theta is equal to

If theta =(pi)/(2 ^(n) +1), then cos theta cos 2 theta cos 2^(2) theta …cos 2 ^(n-1)theta is equal to

The value of (cos3 theta)/(2cos2 theta-1) is equal to cos theta(b)sin theta (c) tan theta(d) none of these

If cos alpha + cosbeta=a, sinalpha + sinbeta=b and theta is the arithmetic mean between alpha and beta , then (sin2theta + cos 2theta) is equal to :

If cos alpha + cosbeta=a, sinalpha + sinbeta=b and theta is the arithmetic mean between alpha and beta , then (sin2theta + cos 2theta) is equal to :