sinθ = 0.7 then cosθ, 0 ≤ θ < 90° is?

A. 0.3

B. $$\sqrt {0.49} $$

C. $$\sqrt {0.51} $$

D. $$\sqrt {0.9} $$

Answer: Option C

Solution(By Examveda Team)

$$\eqalign{ & \sin \theta = 0.7 \cr & \Rightarrow {\sin ^2}\theta + {\text{co}}{{\text{s}}^2}\theta = 1 \cr & \Rightarrow {\left( {0.7} \right)^2} + {\text{co}}{{\text{s}}^2}\theta = 1 \cr & \Rightarrow 0.49 + {\text{co}}{{\text{s}}^2}\theta = 1 \cr & \Rightarrow {\text{co}}{{\text{s}}^2}\theta = 1 - 0.49 \cr & \Rightarrow {\text{cos}}\theta = \sqrt {0.51} \cr} $$