Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

If $sin \theta = \frac{12}{13}$, then $\frac{sin^2 \theta-cos^2\theta}{2cos\theta sin \theta}× cot^2 \theta=?$

Options:

$\frac{595}{1152}$

$\frac{119}{864}$

$\frac{119}{144}$

$\frac{595}{3456}$

Correct Answer:

$\frac{595}{3456}$

Explanation:

sin θ = \(\frac{12}{13}\)

{ sin θ = \(\frac{P}{H}\) }

By using pythagoras theorem,

P² + B² = H²

12² + B² = 13²

B = 5

Now,

\(\frac{sin² θ - co²s θ}{2cosθsinθ}\) × cot² θ

= \(\frac{(12/13)² - (5/13)²}{2×5/13×12/13 }\) × ( 5/12)²

= \(\frac{144/169 - 25/169}{120/169 }\) × 25/144

= \(\frac{119}{120 }\) × 25/144

= \(\frac{595}{3456 }\) sin2θcos2θ2cosθsinθ×cot2θ=?