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📐 Mathematics  ·  Straight Lines  ·  JEE

The parabola y² = 4ax has focus at:

Answer: (a,0).

  • A (a,0)
  • B (-a,0)
  • C (0,a)
  • D (0,-a)

Correct answer: A. (a,0)

Explanation: Standard parabola y² = 4ax: vertex at origin, focus at (a,0), directrix x = -a.

Slope as Rise over Runxy(x₁,y₁)(x₂,y₂)run = x₂−x₁rise = y₂−y₁m = rise/run = (y₂−y₁)/(x₂−x₁) = tanθ

The slope of a line is the ratio of vertical change (rise) to horizontal change (run) between any two points on it - equivalently, the tangent of the angle θ the line makes with the positive x-axis.

Concept context

Points, lines, and curves on the Cartesian plane

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