Ecaluate
`[{:(cosalphacosbeta,cosalphasinbeta,-sinalpha),(-sinbeta,cosbeta,0),(sinalphacosbeta,sinalphasinbeta,cosalpha):}]`

Prove that |[cos alpha cos beta, cos alpha sin beta , sin alpha],[-sinbeta,cosbeta,0],[sinalpha cosbeta, sinalpha sinbeta, cos alpha]|=cos2alpha

If cosalpha+cosbeta=0=sinalpha+sinbeta , then cos2alpha+cos2beta=?

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

Evaluate : Delta=|{:(0,sinalpha,-cosalpha),(-sinalpha,0,sinbeta),(cosalpha,-sinbeta,0):}| .

The determinant D=|{:(cos(alpha+beta),-sin(alpha+beta),cos2beta),(sinalpha,cosalpha,sinbeta),(-cosalpha,sinalpha,cosbeta):}| is independent of :-

Show by vector method that sin(alpha-beta)=sinalphacosbeta-cosalpha sinbeta.

If A=[(0,sin alpha, sinalpha sinbeta),(-sinalpha, 0, cosalpha cosbeta),(-sinalpha sinbeta, -cosalphacosbeta, 0)] then (A) |A| is independent of alpha and beta (B) A^-1 depends only on beta (C) A^-1 does not exist (D) none of these

If cosalpha+cosbeta=0=sinalpha+sinbeta , then prove that cos2alpha +cos2beta=-2cos(alpha +beta) .

If neither alpha nor beta is a multiple of pi/2 and the product AB of matrices A=[(cos^2alpha, cosalpha sin alpha),(cosalpha sinalpha, sin^2alpha)] and B=[(cos^2beta, cosbeta sinbeta),(cosbetasinbeta, sin^2beta)] is a null matrix then alpha- beta is (A) 0 (B) an odd mutiple of pi/2 (C) a multiple of pi (D) none of these