DOUBLE ANGLE TRIG IDENTITIES WORKSHEET

Problem 1 :

The expression 2sin 30° cos 30° has the same value as

a. sin 15°      b. cos 60°     c. sin 60°        d. cos 15°

Solution

Problem 2 :

The expression csc A sin 2A is equivalent to

a. 2sin A        b. 2        c. 2cos A      d. 2cot A

Solution

Problem 3 :

If sin A = 2/3, find cos 2A.

Solution

Problem 4 :

If sin A = 3/5, find cos 2A.

Solution

Problem 5 :

If θ is in Quadrant II and cos θ = -3/4, find an exact value for sin 2θ.

Solution

Problem 6 :

Solution

Problem 7 :

2sin x cos x - cos 2x = 2sin²x - 1 + sin 2x

Solution

Problem 8 :

cos²x + tan²x sin²x = sec²x sin²x + cos2x

Solution

Problem 9 :

Solution

Problem 10 :

1 + cos 2x -   tan 4x cos 4x = 2cos²x - sin 4x

Solution

Problem 11 :

Solution

Problem 12 :

Solution

Problem 13 :

Solution

Problem 14 :

Solution

Problem 15 :

Solution