Cartesian and parametric equations and asymptotes for a hyperbola

Cartesian and parametric equations and asymptotes for a hyperbola

Understanding of Hyperbola Concepts

  • A hyperbola is a type of curve formed by intersecting a cone with a plane at an angle smaller than the slope of the cone.
  • Hyperbolae have two disconnected parts called branches, with points on one branch having negative x values and the other positive.
  • The point of symmetry of each branch is known as the vertex. The line of symmetry through the vertices is the major axis.
  • The asymptotes of a hyperbola are the lines which the curve approaches but never quite reaches. The hyperbola is symmetric with respect to these axes.

Cartesian and Parametric Equations of a Hyperbola

  • The standard Cartesian equation for a hyperbola centred at the origin, with its major axis vertical is given by: (y-y_0)^2/a^2 - (x-x_0)^2/b^2 = 1.
  • If the major axis is horizontal, the equation becomes: (x-x_0)^2/a^2 - (y-y_0)^2/b^2 = 1.
  • Hyperbolae can also be expressed using parametric equations. The standard parametric equations for a hyperbola centred at the origin with its major axis vertical are x = x_0 + b*sec(theta) and y = y_0 + a*tan(theta).
  • For major axis horizontal, the parametric equations are x = x_0 + a*sec(theta) and y = y_0 + b*tan(theta).

Asymptotes of a Hyperbola

  • The asymptotes of a hyperbola are given by the equations y = mx + c, where m is the gradient, and c is the y-intercept.
  • For a hyperbola with the equation (y-y_0)^2/a^2 - (x-x_0)^2/b^2 = 1, the asymptotes are given by: y = y_0 ± (a/b)(x - x_0).
  • For a hyperbola with the equation (x-x_0)^2/a^2 - (y-y_0)^2/b^2 = 1, the asymptotes are given by: y = y_0 ± (b/a)(x - x_0).

Practical Tips for Solving Problems

  • Remember that the vertices of the hyperbola are located at y0±a if the major axis is vertical, and at x0±a if the major axis is horizontal.
  • When converting from Cartesian to parametric equations, secant and tangent will be in terms of the angle from the origin to the point on the hyperbola.
  • For asymptote equations, it is helpful to start by drawing a rough sketch of the hyperbola shape to ascertain the position of the axes and the asymptotes.
  • When calculating the gradient of the asymptotes, remember that it’s ±a/b for a vertical major axis and ±b/a for a horizontal major axis.
  • In all sections of a hyperbola problem, be mindful of the signs associated with the terms in the equations as they discern the direction and position of the hyperbola.