Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

The value of \(\frac{cos^6θ + sin^6θ + 3sin^2θ cos^2θ}{cosec θ sec θ ( 1 - sin θ - cos θ) ( 1+ sin θ + cos θ)}\) is ?

Options:

\(\frac{1}{2}\)

-\(\frac{1}{2}\)

0

1

Correct Answer:

-\(\frac{1}{2}\)

Explanation:

Here,

⇒ cos6 θ + sin6 θ + 3sin2 cos2 θ

= cos6 θ + sin6 θ + 3sin2 cos2 θ (sin2 θ + cos2 θ)

= (cos2 θ + sin2 θ)3 = 1

Now,

= \(\frac{1}{cosec θ sec θ ( 1 - (sin θ + cos θ)(1 + (sin θ + cos θ)}\)

= \(\frac{1}{cosec θ sec θ (1^2 - (sinθ + cosθ)^2)}\)

= \(\frac{1}{cosec θ sec θ ( - 2sin θ cos θ) }\)

= - \(\frac{1}{2}\)