If `alpha` and `beta` are the roots of `x^2-px+q=0`, then the value of `|[1,cos(beta-alpha),cosalpha],[cos(alpha-beta),1,cosbeta],[cosalpha,cosbeta,1]|` is

If tan alpha and tan beta are the roots of the equation x^(2) +px + q = 0 , then the value of sin^(2) (alpha +beta) + p cos (alpha + beta) sin (alpha + beta) + q cos^(2) (alpha + beta) is

f(alpha,beta) = cos^2(alpha)+ cos^2(alpha+beta)- 2 cosalpha cosbeta cos(alpha+beta) is

sinalpha+sinbeta=a ,cosalpha+cosbeta=b=>sin(alpha+beta)

If cosalpha=cosbeta , then alpha+beta= ____

If cosalpha+cosbeta=0=sinalpha+sinbeta" then "cos2alpha+cos2beta

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

If 0

Using vectors, prove that cos(alpha-beta)=cosalpha cosbeta+sinalphasinbeta