The locus of the point `(2sec alpha cos beta, 2 sec alpha sin beta, 2tanalpha)` is

The locus of the point (r sec alpha cos beta, r sec alpha beta, r tan alpha) is

The locus of the point (r cos alpha cos beta, r cos alpha sin beta, r sin alpha) is

" Locus of the point ",[(r sec alpha*cos beta,r sec alpha*sin beta,r tan alpha) is"

If tan 2alpha = cot 2beta , then sec(alpha + beta) =

The value of sin^2 alpha cos^2 beta + cos^2 alpha sin^2 beta + sin^2 alpha sin^2 beta +cos^2 alpha cos^2 beta is

(cos alpha + cos beta) ^ (2) + (sin alpha + sin beta) ^ (2) =

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