If y = cos(2x), then dy/dx = ?
Question 1
Q1. If y = cos(2x), then dy/dx = ?
Answer: -2sin(2x)
Explanation: Using the chain rule, if y = cos(u), then dy/dx = -sin(u)(du/dx), so dy/dx = -sin(2x) * 2 = -2sin(2x).