Prove that: `(cosalpha-cosbeta)^2+(s inalpha-s inbeta)^2=4sin^2((alpha-beta)/2)^(\ )`

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

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

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

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

(1+cosalphacosbeta)^2-(cosalpha+cosbeta)^2=

(cos alpha+cos beta)^(2)+(s in alpha+s in beta)^(2)=lambda cos^(2)((alpha-beta)/(2)) write the value of lambda

Prove that: cos2 alpha cos2 beta+sin^(2)(alpha-beta)-sin^(2)(alpha+beta)=cos2(alpha+beta)

Prove that: sin alpha+sin beta+sin gamma-sin(alpha+beta+gamma)=4sin((alpha+beta)/(2))*sin((beta+gamma)/(2))*sin((gamma+alpha)/(2))