Trigonometry

Simplify: sin²(π/8 + A/2) - sin²(π/8 - A/2).

If tan A = 1/7 and tan B = 1/3, then cos 2A is equal to:

The expression (1 + sin 2θ + cos 2θ) / (1 + sin 2θ - cos 2θ) simplifies to:

Find value of cot 7.5°.

Simplify: sin(A-B)/cos A cos B + sin(B-C)/cos B cos C + sin(C-A)/cos C cos A.

What is the value of tan 3A - tan 2A - tan A?

If A + B + C = π, then sin 2A + sin 2B + sin 2C is:

Simplify: cos³ A sin 3A + sin³ A cos 3A.

What is the value of sin 10° sin 50° sin 70°?

If cos A / a = cos B / b = cos C / c, then triangle ABC is:

Evaluate: cos 12° + cos 84° + cos 132° + cos 156°.

Simplify: (cos A + sin A) / (cos A - sin A) - (cos A - sin A) / (cos A + sin A).

What is the value of tan 9° - tan 27° - tan 63° + tan 81°?

If sin A + sin B = x and cos A + cos B = y, then tan((A+B)/2) is:

Simplify: 1 / (1 + sin² A) + 1 / (1 + cosec² A).

Value of sin² 5° + sin² 10° + ... + sin² 90° is:

If A + B + C = 180°, find value of cot B cot C + cot C cot A + cot A cot B.

What is the simplified form of cos⁴ θ - sin⁴ θ?

If sin A + cos A = m, then sin 2A is:

Evaluate: tan 15°.