If alpha +beta + gamma = 2theta then costheta+`cos(theta-alpha)+cos(theta-beta)+ cos(theta-gamma)`

If alpha+beta+gamma=2 theta ,then cos theta + cos(theta - alpha) + cos(theta - beta) + cos(theta - gamma) =

If cos alpha + cos beta + cos gamma = 0 and also sin alpha + sin beta + sin gamma= 0, then prove that: cos 3 alpha + cos 3beta + cos 3gamma = 3 cos (alpha + beta + gamma)

Let A and B denote the statements A : cos alpha + cos beta + cos gamma =0 B : sin alpha + siin beta + sin gamma = 0 If cos(beta - gamma) + cos (gamma -alpha) + cos (alpha -beta) = - (3)/(2) , then

Prove that : cos^2 (beta-gamma) + cos^2 (gamma-alpha) + cos^2 (alpha-beta) =1+2cos (beta-gamma) cos (gamma-alpha) cos (alpha-beta) .

If alpha and beta are the solution of a cos theta + b sin theta = c , then

If theta is eliminated from the equations x=a"cos"(theta-alpha) and y=bcos(theta-beta), then (x^2/a^2)+(y^2/b^2)-(2xy)/(ab)cos(alpha-beta) is equal to (a) sec^2(alpha-beta) (b) cos e c^2(alpha-beta) (c) cos^2(alpha-beta) (d) sin^2(alpha-beta)

The expression cos^(2)(alpha + beta + gamma) + cos^(2)(beta + gamma) + cos^(2)alpha - 2cos alpha cos(beta + gamma)cos(alpha + beta + gamma) is (a) independent of alpha (b) independent of beta (c) dependent on gamma only (d) dependent on alpha, beta, gamma

cos alpha sin (beta-gamma) + cos beta sin (gamma-alpha) + cos gamma sin (alpha-beta)=

Let alpha, beta, gamma be the measures of angle such that sin alpha+sin beta+sin gamma ge 2 . Then the possible value of cos alpha + cos beta+cos gamma is

Under rotation of axes through theta , x cosalpha + ysinalpha=P changes to Xcos beta + Y sin beta=P then . (a) cos beta = cos (alpha - theta) (b) cos alpha= cos( beta - theta) (c) sin beta = sin (alpha - theta) (d) sin alpha = sin ( beta - theta)