Lesson 4: 9.5 Polar Coordinates
Duration of Days: 2
Lesson Objective
1. Plot points and find multiple representations of points in the polar coordinate system.
2. Convert points from rectangular to polar form and vice versa.
3. Convert equations from rectangular to polar form and vice versa.
How do you describe the position of a point in a plane using distance and angle rather than x- and y-coordinates?
Polar Axis
Polar Coordinates
Pole
Rectangular Coordinates
HSN-CN.B.4 - Represent complex numbers on the complex plane in rectangular and polar form (including real and imaginary numbers), and explain why the rectangular and polar forms of a given complex number represent the same number.
Use Khan Academy Resources
Students will learn about graphing points in terms of their position from a fixed point and its directed angle using polar coordinates.
You can use polar coordinates in mathematical modeling. For instance, you can use polar coordinates to model the path of a passenger car on a Ferris wheel.
Some students may be confused by a negative value of r, since they are used to r representing radius, which is positive.
When graphing polar coordinates, remind students to always start at zero degrees and move counterclockwise if the angle is positive.
Remind students to refer to the unit circle when evaluating the basic trigonometric functions.
Use Common Assessments
Pre-Calculus with Limits Resources