[" 19.Prove that "],[" (i) "(cos alpha-cos beta)^(2)+(sin alpha-sin beta)^(2)=4sin^(2)((alpha-beta)/(2))]

Prove that (cos alpha - cos beta)^(2) +(sin alpha - sin beta)^(2) = 4 "sin"^(2) (alpha-beta)/2

Prove that (cos alpha-cos beta)^2+(sin alpha-sin beta)^2=4sin^2((alpha-beta)/2)

(cos alpha-cos beta) ^ (2) + (sin alpha-sin beta) ^ (2) = 4 (sin ^ (2) (alpha-B)) / (2)

Prove that (cos alpha+cos beta)^(2)+(sin alpha+sin beta)^(2)=4cos^(2)((alpha-beta)/(2))

Prove that : (cos alpha+cos beta)^(2)+(sin alpha+sin beta)^(2)=4cos^(2)((alpha-beta)/(2))

(cos alpha + cos beta) ^ (2) + (sin alpha-sin beta) ^ (2) = 4 (cos ^ (2) (alpha + beta)) / (2)

Prove that (cos alpha+cos beta)^(2)+(sin(alpha)+sin beta)^(2)=4cos^(2)((alpha-beta)/(2))

Prove that (cos alpha+cos beta)^(2)+(sin alpha -sin beta)^(2)=4 cos^(2) ((alpha+beta)/(2))

For alpha , beta in R , prove that (cos alpha + cos beta )^(2)+ (sin alpha + sin beta )^(2)=4cos^(2). ((alpha-beta))/(2)

Prove that : (cos alpha + cos beta)^2 + (sin alpha + sin beta)^2 = 4 cos^2 ((alpha-beta)/(2))