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)
andy = y_0 + a*tan(theta)
. - For major axis horizontal, the parametric equations are
x = x_0 + a*sec(theta)
andy = 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 atx0±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.