[" 4.If "sin(theta+alpha)=a" and "sin(theta+beta)=b," then "],[cos2(alpha-beta)-4ab cos(alpha-beta)=]

If sin(theta+alpha)=a and sin(theta+beta)=b then cos2(alpha-beta)-4abcos(alpha-beta) is equal to

If sin(theta+alpha)=a and sin(theta+beta)=b, prove that cos2(alpha-beta)-4ab cos(alpha-beta)=1-2a^(2)-2b^(2)

s(theta-alpha)=a and cos(theta-beta)=b, then sin^(2)(alpha-beta)+2ab cos(alpha-beta)=

If sin (theta + alpha) = a and sin (theta + beta) = b,"then" cos 2 (alpha - beta) - 4ab cos (alpha - beta) =

If cos(theta-alpha)=a , sin(theta-beta)=b then cos^2(alpha-beta)+2 ab sin(alpha-beta) is equal to

If cos(theta - alpha)=a, cos(theta-beta)=b , then sin^(2)(alpha -beta) + 2abcos(alpha-beta)=0

If cos(theta-alpha)=a and cos(theta-beta)=b then the value of sin^(2)(alpha-beta)+2ab cos(alpha-beta)

If cos (theta -alpha) =a, sin (theta - beta) =b, then cos ^(2) (alpha - beta) + 2 ab sin (alpha - beta) is equal to