If `cos^-1 alpha + cos^-1 beta + cos^-1 gamma = 3pi` then `alphabeta + betagamma+ gammaalpha` equals

If cos^-1 alpha + cos^-1 beta + cos^-1 gamma = 3 pi , then alpha(beta + gamma) + beta (gamma + alpha) + gamma (alpha + beta) equals

If cos^(-1) alpha + cos^(-1) beta + cos^(-1) gamma = 3pi , then alpha (beta + gamma) + beta(gamma + alpha) + gamma(alpha + beta) equal to

If cos^(-1) alpha + cos^(-1) beta + cos^(-1) gamma = 3pi , then alpha (beta + gamma) + beta(gamma + alpha) + gamma(alpha + beta) equal to

If cos ^(-1) alpha+cos ^(-1) beta+cos ^(-1) gamma=3 pi then alpha(beta+gamma)+beta(gamma+alpha)+gamma(alpha+beta)=

If cos^(-1)alpha+cos^(-1)beta+cos^(-1)gamma=3pi , then alpha(beta+gamma)+beta(gamma+alpha)+gamma(alpha+beta) equals to ______

If cos alpha + cos beta + cos gamma = 0 then cos 3alpha + cos 3beta + cos 3gamma = lambda cos alpha *cos beta*cos gamma where lambda is equal to

If "cos"^(-1)alpha+"cos"^(-1)beta+"cos"^(-1)gamma=3pi , then find alpha(beta+gamma)+beta(gamma+alpha)+gamma(alpha+beta) .

If cos alpha + cos beta + cos gamma = sin alpha + sin beta + sin gamma = 0 , show that cos 3alpha + cos 3 beta + cos gamma = 3 cos (alpha + beta + gamma) and