[" Prove that "],[qquad (" i) "sin80^(@)cos20^(@)-cos80^(@)sin20^(@)=(sqrt(3))/(2)]

sin20^(@)*cos40^(@)+cos20^(@)*sin40^(@)=(sqrt(3))/(2)

(2cos40^(@)-cos20^(@))/(sin20^(@))

(2cos40^(@)-cos20^(@))/(sin20^(@))

(2cos40^(@)-cos20^(@))/(sin20^(@))=?

Prove that (i) sin 70^(@) cos 10^(@) -cos 70^(@) sin 10^(@) =(sqrt(3))/(2) (ii) cos 50^(@) cos 10^(@) -sin 50^(@) sin 10^(@) =(1)/(2) (ii) cos 80^(@) cos 20^(@) + sin 80^(@) sin 20^(@) =(1)/(2) (iv) sin 36^(@) cos 9^(@) + cos 36^(@) sin 9^(@) =(1)/(sqrt(3))

sin20^(@)+sin40^(@)-sin80^(@)=

Prove that (i) " sin " 80^(@) "cos " 20^(@) - " cos " 80^(@) " sin " 20^(@) =(sqrt(3))/(2) (ii) " cos " 45^(@) " cos " 15^(@) - " sin " 45^(@) " sin " 15^(@) = (1)/(2) (iii) " cos " 75^(@) " cos " 15^(@) + " sin " 75^(@) " sin " 15^(2)= (1)/(2) (iv) " sin " 40^(@) " cos " 20^(@) " + cos " 40^(@) " sin " 20^(@) =(sqrt(3))/(2) (v) " cos " 130^(@) " cos " 40^(@) l + " sin " 130^(@) " sin " 40^(@) =0

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

Prove that: sin20^(@)sin40^(@)sin80^(@)=(sqrt(3))/(8)

Prove that,sin20^(@)sin40^(@)sin80^(@)=(sqrt(3))/(8)