cos(30^(2)-A)+cos(30^(@)+A)=sqrt(3)cos A

Prove that cos (30^(@) -A ) cos (30^(@) + A ) + cos (45^(@) - A) cos (45^(@) + A) = cos 2A + (1)/(4) .

Given that (2 sqrt3 cos 30^(@) - 2i sin 30^(@))/(sqrt2 (cos 45^(@) + isin 45^(@)))=A + Bi , find the values of A and B.

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

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

If z_1=sqrt2 (cos 30^(@) +isin60^(@)),z_2=sqrt3 (cos 60^(@) +isin30^(@)) Find R_e(z_1z_2)

Prove that: (cos(60^(@)-A)+sin(30^(@)-A))/(cos(30^(@)-A)-sin(60^(@)-A))= cotA

Prove that: (cos(60^(@)-A)+sin(30^(@)-A))/(cos(30^(@)-A)-sin(60^(@)-A))=cotA

The value of 2 sqrt(2) cos 45^(@) * cos 60^(@) + 2 sqrt(3) sin 30^(@) tan 60^(@) - cos 0^(@) is

cos 10^(@) cos 30^(@) cos 50^(@) cos 70^(@) =(3)/(16)

Prove that cos (30^(@) + x) = (sqrt(3) cos x - sin x)/(2)