Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

If r sinθ = \(\sqrt { 3}\) and r cosθ = 1, the value of r and θ are?

Options:

r = 1, θ = 30°

r = 2, θ = 60°

r = 2, θ = 45°

r = \(\sqrt {3}\), θ = 45°

Correct Answer:

r = 2, θ = 60°

Explanation:

r sinθ = \(\sqrt {3 }\)

r cosθ = 1

squaring and adding

⇒ r2 (sin2θ + cos2θ) = 4

⇒ r2 = 4    (because sin2θ + cos2θ = 1)

\(\frac{r\;sinθ}{r\;cosθ}\) = \(\sqrt { 3}\) ⇒ tanθ = \(\sqrt {3 }\)

⇒ θ = 60°,  r = 2