Trig Identities

What is sin(A + B) + sin(A - B) equal to?

The value of cos(120) is:

If tan A = 3/4, find the value of cos(2A).

Simplify: (sin A + cos A)^2 - 1

Which of the following is tan(2A)?

Value of sin(75) is:

If sin A = 4/5, find sin(2A).

Simplify cos^4 A - sin^4 A.

What is the value of 2 sin(15) cos(15)?

Simplify (1 - cos 2A) / (1 + cos 2A).

If tan A = 1/2 and tan B = 1/3, find tan(A + B).

The value of cos^2(15) - sin^2(15) is:

Simplify cos(A - B) - cos(A + B).

What is the value of tan(15)?

If sin A = 1/sqrt(2), find cos(2A).

The expression 2 cos^2(theta/2) - 1 is equal to:

What is 1 - 2 sin^2(22.5) equal to?

Simplify sin(3A) / sin A - cos(3A) / cos A.

If A + B = 45, then (1 + tan A)(1 + tan B) = ?

The value of cos 20 cos 40 cos 80 is: