8.2.2 – graphing polar points, converting equations
TRANSCRIPT
8.2.2 – Graphing Polar Points, Converting Equations
• To graph polar coordinates, we will do it as a combination of:– 1) Graphing cartesian coordinates– 2) Using the unit circle
The Polar Plane
• A series of circles, with increasing radii • Each radius, for our purposes, is an increase of one unit
• Notice angle measures
The Polar Plane
• To plot on the polar plane• 1) Find the radius, givenby r, in the ordered pair, (r, ϴ)
• 2) Find angle given byϴ, in the ordered pair (r, ϴ)
• Example. Plot the polar point (3, π/2)
• Example. Plot the polar point (1, 4π/3)
• Example. Plot the polar point (2, 3π/4)
Negative Radius
• We really do not have such a thing as a “negative radius” in a real life context– Distance; should be positive
• In the Polar coordinate plane, though, a negative radius may occur
• The radius, -r, is acts as a 180 degree reflection
• Example. Plot the polar point (-1, 11π/6)
• Assignment• Pg. 628• 1-6 all• Plot 13 and 14 which you converted last night
to polar points