Trigonometric Identities

5. Simplify the trigonometric expression. 1/(1+sin(theta)) + (1/(1-sin(theta))

B. 2sec^2(theta)

2. Which identity could be the missing step to verify the identity (cos theta)(csc theta) = cot(theta)?

B. cos(theta) (1/sin(theta)) = cot(theta)

4. Which of the following is a trigonometric identity?

C. cos^2(theta) - sin^2(theta) = 1 - 2sin^2(theta)

1. What is the domain of validity for csc(theta)0 = 1/sin(theta)?

D. all real numbers except multiples of pi.

3. Which identity is NOT used in the proof of the identity 1 + cot^2(theta) = csc^2(theta)?

D. tangent identity