Find the one which does not belong to that

sin10˚ x sin20˚ x sin40˚ =? 

Evaluate the following:

sin 50° × cos 20° − sin 20° × cos 50°

Simplify the following trigonometric expression: 

15 cos 25° cosec 65° − 5 cot 80° cot 10°

If sinθ = 5/13 for an acute angle θ, find:

(a) cosθ, (b) tan(90° − θ).

If tan theta = 5/12 and theta is acute, then the value of (1 - sin theta)/(1 + sin theta) is:

If 9sin²x + 5cos²x − 7 = 0, then find the value of sinx, given that 0° < x < 90°.

Simplify (cos13°+sin 13°) /(cos13°-sin13°)

Evaluate the following:

cos 45° × cos 45° − sin 45° × sin 45°

Find the maximum value of 18 sin A + 7 cos A.