Prove that `5 cos theta+3cos(theta+(pi)/(3))+3` lies between -4 and 10.

Prove that 5costheta+3cos(theta+pi/3)+3 lies between -4a n d10.

Prove that 5costheta+3cos(theta+pi/3)+3 lies between -4 and 10 .

Prove that 5costheta+3cos(theta+pi/3)+3 lies between -4a n d10.

Prove that the value of 5 costheta+3 cos(theta+pi/3) lies between -7 and 7.

Prove that : sec theta + cos theta != 3/2

(2+sqrt(3)) sin theta +2cos theta lies between

Prove that: 4\ costhetacos\ (pi/3+theta)cos(pi/3-theta)=cos3theta

Prove that: cos^3theta+cos^3 (theta- (2pi)/n)+cos^3 (theta- (4pi)/n)+… to n terms =0

Solve cos theta * cos 2 theta * cos 3 theta = (1)/( 4), 0 le theta le pi

Prove that cos theta + cos (120^(@) + theta) + cos ( 120^(@)-theta) =0. Hence deduce that cos ^(3) theta + cos ^(3) ( 120^(@) + theta ) + cos^3( 120^(@)-theta) = 3/4 cos 3 theta.