[" 6."],[" Qillot कosit: "],[" (i) "cos theta cos(60^(@)-theta)cos(60^(@)+theta)=(1)/(4)cos3 theta]

cos(60^(@)-theta)cos(60^(@)+theta)=(1)/(4)(4cos^(2)theta-3)

Prove that cos thetacos(60^(@)- theta)cos(60^(@)+theta) = 1/4 cos 3 theta

Prove that: |cos theta cos(60^(@)-theta)cos(60^(@)+theta)<=(1)/(4) for all values of theta

Prove that 4 cos theta cos (60^(@) + theta) cos (60^(@) - theta) = cos 3theta .

cos^(2)theta+cos^(2)(60^(@)+theta)+cos^(2)(60^(@)-theta)=3/2

cos^(2)theta+cos^(2)(60^(@)+theta)+cos^(2)(60^(@)-theta)=3/2

Prove that sin (30^(@) + theta) + cos (60^(@) + theta) = cos theta

Evaluate sin(30^(@)+theta)-cos(60^(@)-theta) .

Evaluate sin(30^(@)+theta)-cos(60^(@)-theta) .

Statement-1: The vlaue of cos20^(@)cos40^(@)cos60^(@)cos80^(@)is1/16. Statement-2: for any theta, cos thetacos(60^(@)-theta)cos(60^(@)+theta)=1/4cos3theta