If `cos(theta-phi)`, `cos(theta)`, `cos(theta+phi)` are in HP, the the value of `cos(theta)sec(phi/2)` is

If cos(theta+phi)=m cos(theta-phi) then tan theta is equal to

If cos (theta +phi)=m cos(theta-phi) ,then the value of (1-m)/(1+m)cot phi .

If sin theta+sin phi=(1)/(2) and cos theta+cos phi=1 then find the value of cot((theta+phi)/(2))

If sin theta sin phi - cos theta cos phi+1 =0 then the value of 1+ cot theta tan phi is-

If a=costheta+isintheta, b=cos phi+isinphi ,find the values of cos(theta+phi) and cos(theta-phi) in terms of a and b.

Compute the following: {:[(sin(theta+phi), cos(theta+phi)),(sin(theta - phi),cos(theta-phi))] +[(sin(theta-phi), cos(theta-phi)),(sin(theta+phi), cos(theta+phi))]

If cos theta=(2cos phi-1)/(2-cos phi), then find the value of tan((theta)/(2))

If theta and phi are acute angles, sin theta=1/2, cos phi= 1/3 , then the value of (theta + phi) is:

Suppose theta and phi(ne 0) are such that sec (theta+phi), sec theta and sec (theta-phi) are in A.P. If cos theta=kcos((phi)/(2)) for some k, then k is equal to

Suppose theta and phi(ne 0) are such that sec (theta+phi), sec theta and sec (theta-phi) are in A.P. If cos theta=kcos((phi)/(2)) for some k, then k is equal to