Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

The value of $\frac{sinA}{cot A+cosec A }-\frac{sinA}{cot A−cosec A}-1$ is:

Options:

$\frac{1}{2}$

1

0

2

Correct Answer:

1

Explanation:

\(\frac{sinA}{cotA + cosecA }\) - \(\frac{sinA}{cotA - cosecA }\) - 1

= \(\frac{sinA}{cosA/sinA + 1/sinA }\) - \(\frac{sinA}{cosA/sinA - 1/sinA}\) - 1 

= \(\frac{sin²A}{cosA + 1 }\) - \(\frac{sin²A}{cosA - 1}\) - 1

= \(\frac{sin²A}{1 + cosA }\) + \(\frac{sin²A}{1 - cosA }\) - 1

= \(\frac{sin²A ( 1 - cosA ) + sin²A ( 1 + cosA ) }{1 - cos²A }\) - 1

{ using , sin²A + cos²A = 1 }

= \(\frac{2sin²A}{sin²A }\) - 1

= 2 - 1

= 1