" 22e "(cos^(2)alpha-cos^(2)beta)/(cos^(2)alpha*cos^(2)beta)=tan^(2)beta-tan^(2)alpha

(cos^2alpha-cos^2beta)/(cos^2alpha cos^2beta)=tan^2beta-tan^2alpha

Prove that (cos^2 alpha - cos^2 beta)/(cos^2 alpha*cos^2 beta) = tan^2 beta - tan^2 alpha

cos^(2)(alpha+beta)+cos^(2)(alpha-beta)-cos2alpha cos2beta=

Prove that (cos2 alpha-cos 2 beta)/(sin2 alpha+sin2 beta)=tan(beta-alpha)

Show that cos^(-1)((cos alpha+cos beta)/(1+cos alpha cos beta))=2tan^(-1)(tan((alpha)/(2))tan((beta)/(2)))

Prove that cos^(-1)[(cos alpha +cos beta)/(1+cos alpha cos beta)]=2tan^(-1)("tan"(alpha)/(2)"tan"(beta)/(2))

Show that cos^(-1) ((cos alpha+cos beta)/(1+cosalpha cosbeta))=2 tan^(-1)(tan (alpha/2) tan (beta/2))

Prove that cos theta =(cos alpha- cos beta)/(1 -cos alpha*cos beta) ⇔ tan theta/2 = pm tan alpha/2 *cot beta/2 .

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