4cos^(3)40^(@)-3sin50^(@)=

If (4cos^(2)40^(@)-3)(3-4sin^(2)40^(@))=a+b cos20 then find the value of (a-b)

Prove that cos20^(@)cos40^(@)-sin5^(@)sin25^(@)=(sqrt(3)+1)/4

What is the value of 4(cos^(2)(10^(@))+cos^(2)(50^(@))-sin40^(@)sin80^(@))

Prove that (sin70^(@)-cos40^(@))/(cos50^(@)-sin20^(@)) = 1/(sqrt(3)) .

(cos30^(@)-sin20^(@))/(cos40^(@)+cos20^(@))=(4)/(sqrt(3))cos40^(@)cos80^(@)

Prove that, (cos30^(@) - sin 20^(@))/(cos 40^(@) + cos20^(@)) = 4/sqrt3 cos40^(@) cos 80^(@)

The value of {cos(40^(@)+theta)-sin(50^(@)-theta)} is

Prove that cos 20^(@) cos 40^(@) - sin5^(@) sin 25^(@) = (sqrt(3)+1)/(4) .

i) Prove that: cos^(3)2A+3cos2A = 4(cos^(6)A-sin^(6)A) ii) Prove that: 4(cos^(3)10^(@) + sin^(3)20^(@)) = 3(cos10^(@)+sin20^(@))

Evaluate : sin50^(@)cos40^(@)+cos40^(@)+cos50^(@)sin40^(@)