Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

If cos 27° = \(x\); then the value of tan 63° is?

Options:

\(\frac{x}{\sqrt {1-x^2}}\)

\(\frac{1}{\sqrt {1+x^2}}\)

\(\frac{x}{\sqrt {1+x^2}}\)

\(\frac{\sqrt {1-x^2 }}{x}\)

Correct Answer:

\(\frac{x}{\sqrt {1-x^2}}\)

Explanation:

cos27° = x = sin63°        [because cos ∝ = sin (90-∝)]

⇒ cos63° = \(\sqrt {1-sin^2 63 }\)          {Cos ∝ = \(\sqrt{1 - sin^2 ∝}\)}

⇒ cos63° = \(\sqrt {1-x^2 }\)

∴ tan63° = \(\frac{sin63°}{cos63°}\) = \(\frac{x}{\sqrt {1-x^2}}\)