" 9.(a) "2sin75^(@)cos15^(@)=(1)/(2)(2+sqrt(3))" ."

Prove that : (i) "sin"105^(@)+cos105^(@)=(1)/(sqrt(2)) (ii) cos105^(@)+cos15^(@)="sin"75^(@)-"sin"15^(@)

4sin^(3)75^(0)-3cos15^(0)= (1)/(2) (1)/(sqrt(2)) (1)/(sqrt(3)) sqrt(3)

Prove that (i) " 2 cos " 45^(@) " cos " 15^(@)=((sqrt(3)+1))/(2) " "(ii) 2 " sin " 75^(@) " sin " 15^(@)=(1)/(2) (iii) " cos " 15^(@) - " sin " 15 =(1)/(sqrt(2))

(sin 75^(@) - sin 15 ^(@))/( cos 75^(@) + cos 15 ^(@)) = (1)/(sqrt3)

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

(sin75^(@) - sin 15^(@))/(cos 75^(@) + cos 15^(@)) A) -sqrt3 B) sqrt3 C) (1)/(sqrt3) D) (1)/(sqrt3)

What is the value of (tan 9^(@) tan 23^(@) tan 60^(@) tan67^(@) tan 81^(@))/("cosec"^(2)72^(@)+cos^(2)15^(@)-tan^(2)18^(@)+cos^(2)75^(@))? (a) (1)/(2 sqrt(3)) (b) (sqrt(3))/(2) (c) (1)/(sqrt(3)) (d) 2 sqrt(3)

The value of sin^(2)75^(@)-sin^(2)15^(0) is 1/2 b.sqrt(3)/2 c.1 d.0

The value of 2 sin 15^(@).cos75^(@)

Prove that: sin15^(@)=(sqrt(3)-1)/(2sqrt(2))