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Define and classify asymptotes of a curve

Short answer

Types include horizontal (y = k), vertical (x = h), and oblique (y = mx + c, m ≠ 0). Also by inspection and for polar curves where r → ∞.

State the types of asymptotes to a curve.

An asymptote of a curve is a straight line such that the distance of a point on the curve from the line tends to zero as the point goes to infinity along the curve. It is the tangent to the curve at infinity.

Types

  1. Asymptote parallel to the x-axis (horizontal): a line y = k. It is found by equating to zero the coefficient of the highest power of x in the equation of the curve.
  2. Asymptote parallel to the y-axis (vertical): a line x = h. It is found by equating to zero the coefficient of the highest power of y.
  3. Oblique asymptote (inclined): a line y = mx + c with m ≠ 0, ∞. The slopes m are the roots of φₙ(m) = 0, where φₙ is the highest-degree part of the equation, and c follows from φₙ₋₁(m) + c φₙ′(m) = 0.

Besides these, a curve may have asymptotes by inspection (for example a hyperbola's asymptotes differ from the curve only by a constant) and, in advanced work, circular or curvilinear asymptotes. For polar curves, an asymptote is found from r → ∞ at the angle where 1/f(θ) = 0.

✓ Answer checked by Claude Opus 5.5 (high effort)

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