Advertisements
Advertisements
Question
Find θ if 0° < θ ≤ 90°.
cos θ = 2 cos2 30° − 1
Sum
Advertisements
Solution
Given:
0° < θ ≤ 90°
cos θ = 2 cos2 30° − 1
= cos(2 × 30°)
= cos 60°
= `1/2` ...[Since 0° < θ ≤ 90°, cos θ = `1/2` gives]
= θ = 60°
shaalaa.com
Is there an error in this question or solution?
