If cos x = sin y and cot (x - 40°) = tan (50° - y), then the value of x and y are:
x = 70°, y = 20°
x = 75°, y = 15°
x = 85°, y = 5°
x = 80°, y = 10°
The value of tan 315° cot (-405°) is equal to
-1
1
0
2
B.
1
tan 315° . cot (-405°)
[As cot (-θ) = - cot θ]
= - tan 315°. cot 405°
= - tan (360° - 45°). cot (360° + 45°)
= -(-tan 45°) cot 45°
= 1 x 1 = 1
If sin θ + sin2θ = 1, then the value of cos12 θ + 3 cos 10 θ + 3 cos8 θ + cos6 θ - 1 is
0
1
-1
2
If x, y are positive acute angles x + y < 90° and sin (2x - 20°) = cos (2y + 20°), then the values of sec (x + y) is
1
0