Question

!!!! PLEASEEE HELP ME, IDK WHAT TO DO PLEASE !!!!

Express cos in terms of sin.
A. ±√(1 - sin²θ)
B. 1 + sin²θ
C. sin²θ - 1
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Simplify 1/2 (-sin^2 x - cos^2 x).
A. -1 1/2
B. -1/2
C. 1/2
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Simplify tan^2 x + 1/cot^2 x + 1
A. 1/sinx
B. tanx
C. cotx

Answer 1

The first question is A.

The second question is C.

The thid question is B., I think i'm not quit sure sorry