The value of expression `(2sin^2 91^0-1)(2sin^2 92^0-1)(2sin^2 180^0-1)` is equal to 0 (b) `1` (c) `2^(90)` (d) `2^(90)-90`

The value of the expression (1-4sin 10^0 sin 70^0)/(2sin 10^0 ) is- a.1/2 b. 1 c.2 d. none of these

(cos^(2)1^(0)-cos^(2)2^(0))/(2sin3^(0)*sin1^(0)) is equal to

The value of (sin180^(@)+cos90^(@))^(2) is :

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

The value of expression (2(sin1^(0)+sin2^(0)+sin3^(0)+...+sin89^(@)))/(2(cos1^(0)+cos2^(0)++cos44^(0))+1) (a) sqrt(2)(b)(1)/(sqrt(2))(c)(1)/(2)(d)0

The value of the expression (2(sin1^(0)+sin2^(0)+sin3^(0)+...+sin89^(@)))/(2(cos1^(0)+cos2^(0)+...+cos44^(0))+1) equals

The value of sin^(2) 1^(@) + sin^(2) 2^(@) + sin^(2) 3^(@)+ . . . . + sin^(2) 89^(@) + sin ^(2) 90^(@) is

What is the value of [sin(90-A)+cos(180-2A)]//[cos(90-2A)+sin(180-A)]?

If a , b ,\ A are given in a triangle and c_1a n d\ c_2 are two possible values of third side such that c_1^2+c_1c_2+c_2^2=a^2 , then A is equal to 30^0 (b) 60^0 (c) 90^0 (d) 120^0