key term - Symmetry

Definition

Symmetry in mathematics refers to a property where a figure or equation remains invariant under certain transformations, such as reflection or rotation. In polar coordinates, symmetry helps simplify the analysis and graphing of curves.

5 Must Know Facts For Your Next Test

1. A polar curve is symmetrical about the polar axis if substituting $(r, \theta)$ with $(r, -\theta)$ yields the same equation.
2. A polar curve is symmetrical about the line $\theta = \frac{\pi}{2}$ if substituting $(r, \theta)$ with $(-r, -\theta)$ yields the same equation.
3. A polar curve is symmetrical about the pole (origin) if substituting $(r, \theta)$ with $(-r, \theta + \pi)$ yields the same equation.
4. Checking for symmetry can simplify integration limits when finding areas enclosed by polar curves.
5. Identifying symmetry can reduce computational effort by allowing calculations over only part of the curve.

Review Questions

Related terms

Polar Coordinates:

A coordinate system where each point on a plane is determined by an angle and a distance from a reference point.

Parametric Equations:

Equations that express coordinates of points as functions of one or more parameters.

Pole:

The origin in a polar coordinate system.