Geometryhard · Past Paper
The equation of the normal to the circle x^2 + y^2 = 25 at (3, 4) is:
A4x - 3y = 0
B3x - 4y = 0
C3x + 4y = 25
D4x + 3y = 25
✓ Correct Answer: A — 4x - 3y = 0
The normal to a circle at any point passes through the center (0,0). Line through (0,0) and (3,4) is y = (4/3)x => 4x - 3y = 0.
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