Prove that, `4 (cos^(3) 10^(@) + sin^(3) 20 ^(@))=3 (cos 10^(@) + sin 20^(@))`

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^(@))

Prove the following 4(cos^(3)10^(@)+sin^(3)20^(@))=3(cos10^(@)+sin20^(@))

Prove that, (cos 20^(@) + sin 20^(@))/(cos 20^(@) - sin 20^(@)) = tan 65^(@)

Prove the following identity: 4(cos^(3)10^(0)+sin^(3)20^(@))=3(cos10^(0)+sin20^(@))

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

[Prove the following 8cos^(3)10^(@)-8sin^(3)20^(@)-6cos10^(@)+6sin20^(@)=2sqrt(3)

What is the value of (cos 10 ^(@) + sin 20^(@))/( cos 20^(@) - sin 10 ^(@))?

Show that 4(cos^3 10^@+sin^3 20^@)=3(cos10^@+sin20^@)

Prove that sin 20^(@) + sin 140^(@)-cos 10 ^(@) =0

Which of the following numbers is/are twin prime with 5(C)4((cos^(3)10^(0)+sin^(3)20^(@))/(cos10^(0)+sin20^(@)))(D)(cos68^(@))/(sin56^(@)sin34^(0)tan22^(@))