2014 · Q58
What is (sin x − cos x + 1)/(sin x + cos x − 1) equal to?
Elementary MathematicsTrigonometry
- A(sin x − 1)/cos x
- B(sin x + 1)/cos x
- C(sin x − 1)/(cos x + 1)
- D(sin x + 1)/(cos x + 1)
Explanation
Cross-multiplying: (sin x − cos x + 1)cos x = (1 + sin x)(sin x + cos x − 1), an identity.