`cos2 theta+2 costheta` is always

Find the values of theta , for which cos3theta + sin3theta + (2sin2theta-3)(sintheta-costheta) is always positive.

Find the values of theta , for which cos3theta+sin3theta+(2sin2theta-3)\ (sintheta-costheta) is always positive

Find the values of theta , for which cos3theta + sin3theta + (2sin2theta-3)(sintheta-costheta) is always positive.

If theta=30° , show that 3sin theta- 4sin^3 theta= sin theta cos2 theta + costheta sin 2theta .

(sin5theta+sin2theta-sintheta)/(cos5theta+2cos3theta+2cos^2theta+costheta) is equal to

If cos(theta - alpha) , costheta , cos(theta + alpha) are in H.P. then costheta.sec(alpha/2) =

If cos(theta - alpha) , costheta , cos(theta + alpha) are in H.P. then costheta.sec(alpha)/2 =

The minimum value of cos2theta +costheta for all values of theta is :

Minimum value of cos2theta+costheta for all real value of theta is