" 21."sin5A=5cos^(4)A sin A-10cos^(2)A sin^(3)A+sin^(5)A

Prove that, sin5A=5cos^(4)AsinA-10cos^(2)Asin^(3)A+sin^(5)A

sin5A=5cos^4AsinA-10cos^2Asin^3A+sin^5A

1+ cos 10^(@) + cos 20^(@)+ cos 30^(@)= ............... A) 4 cos 5^(@) cos 10^(@) cos 15^(@) B) 4 cos 10^(@) cos 20^(@) cos 30^(@) C) 4 sin 5^(@) sin 10^(@) sin 15^(@) D) 4 sin 10^(@) sin 20^(@) sin 30^(@)

The value of (sin 1^(@) + sin 3^(@) + sin 5^(@) + sin 7^(@))/( cos 1^(@) .cos2^(@).sin4^(@)) is"________"

Prove that: (cos 2A cos 3A-cos 2A cos 7A + cos A cos 10A)/(sin 4A sin 3A -sin 2A sin 5A + sin 4A sin 7A)= cot 6A cot 5A .

The value of (sin 1^(@) +sin 3^(@) + sin 5^(@) +sin 7^(@))/(cos 1^(@)*cos 2^(@)sin 4^(@)) is __________

The value of (sin 1^(@) +sin 3^(@) + sin 5^(@) +sin 7^(@))/(cos 1^(@)*cos 2^(@)sin 4^(@)) is __________

The value of (sin 1^(@) +sin 3^(@) + sin 5^(@) +sin 7^(@))/(cos 1^(@)*cos 2^(@)sin 4^(@)) is __________

(sin A sin2A + sin3A sin6A) / (sin A cos2A + sin3A cos6A) = tan5A

Prove that: (sin5A cos2A-sin6A\ cos A)/(sin A\ sin2A-cos2A cos3A)=t a n A