The value of sin 20^o sin 40^o sin 60^o sin 80^o is equal to

If sin A = ⁴/₅ and cos B = -¹²/₁₃, where A and B tie in first and third quadrant respectively, then cos (A + B) is equal to

The expression tan²∝+ cot² ∝ is

The value of x for the maximum value of√3 cos x + sin x, is

The minimum value of 5 sin²θ + 4 cos²θ is

The maximum value of Sinθ Cosθ is

(tan 7^o) (tan 23^o) (tan 60^o)(tan 67^o)(tan83^o) is

The value of Cos²θ + Sec²θ is always

The value of cos 1^o cos 2^o cos 3^o .... cos 100^o =