Question

Find the Value
A.
B.
C.
D.

Answer 1

C

Explanation:

Using the trig. identity

sin²x + cos²x = 1 ⇒ cosx = ±
`√(1-sin^2x)`

Here sinθ =
`(1)/(2)` , thus

cosθ = ±
`\sqrt{1-((1)/(2))^2 }` = ±
`\sqrt{1-(1)/(4) }` = ±
`\sqrt{(3)/(4) }` = ±
`(√(3) )/(2)`

Since 0 ≤ θ > 90 then cosθ > 0 , thus

cosθ =
`(√(3) )/(2)` → C