# Rewrite the following expression as a - Expert Answers

1.Rewrite the following expression as a simplified expression containing one term.

2.Identify a and ß in the following expression, which is the right-hand side of the formula for cos (a –
ß).
cos (170°) cos (50°) + sin (170°) sin (50°)
A. a = - 170°, ß = 50°
B. a = 170, ß = 50°
C.a = - 50°, ß = 170°
D.a = 50°, ß = - 170°

3.Use trigonometric identities to find the exact value of the expression below.

4.Complete the identity given below.

(sin x - cos x)
A.1 - sin 2x
B.1 - cos 2x
C.1 + cos 2x
D.sin 2x

5. Use a calculator to solve the following equation on the interval  Round the answer to two decimal places.
sin x = -0.29
A.3.44, 5.99
B.0.29, 3.44
C.0.29, 5.99
D.0.29, 1.87

6.Use a half-angle formula to find the exact value of the expression sin 165°.

7.To which of the expressions below is equivalent?

8.Express the product of sin 5x cos 2x as a sum or difference.

9.Use a half-angle formula to find the exact value of the expression cos 112.5°.

10.Solve the problem sin 8x – sin 2x.
A.2 sin 5x cos 3x
B.2 sin 3x
C.2 sin 3x cos 5x
D.2 cos 2x cos 5x

11.Find the exact value of the following by using a sum or difference identity.

sin (185° - 65°)

12.Complete the following identity:
A.sin
B.cot
C.1
D.cot

13. Which expression could be used to fill in the blank in sin x _______ = tan x to create a valid trigonometric identity?
A.cos x
B.sec x
C.tan x
D.sin x

14. Write 2 sin x cos 6x as a sum or difference of trigonometric functions.
A.cos 5x - cos 7x
B.sin 7x - sin 5x
C.sin 7x + sin 5x
D.cos 5x + cos 7x

15.Find the exact value of the expression cos (245° - 5°).

16.Using a double-angle formula, find cos 420°.