If cos(θ) = 2/3, find sin(θ).
Question 1
Q1. If cos(θ) = 2/3, find sin(θ).
Answer: √5/3
Explanation: Using Pythagorean identity, sin²(θ) = 1 - cos²(θ) = 1 - (2/3)² = 5/9, so sin(θ) = √(5/9) = √5/3.