The equation of the normal to the circle x² + y² = 25 at (3, 4) is?
Q1. The equation of the normal to the circle x² + y² = 25 at (3, 4) is?
Answer: 4x - 3y = 0
Explanation: The normal at (x1, y1) to x² + y² = r² is y1*x = x1*y. Here, it's 4x = 3y, or 4x - 3y = 0.