[sin2A=2sin A" is true "shcm A=],[qquad [" Af "Phi," (B) "30]]

sin 2B = 2 sin B is true when B is equal to

sin2A=2sinA is true when A= (a) 0^@ (b) 30^@ (c) 45^@ (d) 60^@

If sin theta+ sin phi = a, cos theta + cos phi = b, find the value of sin ( theta+phi) and cos 2theta + cos 2phi where |b|>|a|

If : sin (theta + phi) = 2 sin (theta - phi), "then" : tan theta = A) tan phi B) 2 tan phi C) 3 tan phi D) 4 tan phi

Eliminate theta " and " phi sin theta + sin phi = a, cos theta + cos phi = b, 0 - phi = alpha

If the line joining the points (a cos theta , b sin theta) and (a cos phi, b sin phi) .Prove that the equation of this lines is x/a "cos" (theta + phi)/2 + y/b"sin" (theta + phi)/2 = "cos" (theta -phi)/2

If x = cos theta cos phi + sin theta sin phi cos psi , y = cos theta sin phi - sin theta cos phi cos psi and z = sin theta sin psi , then x^(2) + y^(2) + z^(2) equals :

If a=cos phi cos psi+sin phi sin psi cos delta, b=cos phi sin psi-sin phi cos psi cos delta, "and" c=sin phi sin delta, then a^2+b^2+c^ 2=