170 likes | 182 Views
Learn how to use polar coordinates for graphing, similar to giving directions with distances and angles. Explore polar functions and symmetry tests. Convert polar to Cartesian coordinates for further analysis.
E N D
10.5: Polar Coordinates Greg Kelly, Hanford High School, Richland, Washington
One way to give someone directions is to tell them to go three blocks East and five blocks South. Another way to give directions is to point and say “Go a half mile in that direction.” Polar graphing is like the second method of giving directions. Each point is determined by a distance and an angle. A polar coordinate pair Initial ray determines the location of a point.
One way to give someone directions is to tell them to go three blocks East and five blocks South. Another way to give directions is to point and say “Go a half mile in that direction.” Polar graphing is like the second method of giving directions. Each point is determined by a distance and an angle. A polar coordinate pair x-axis
Some curves are easier to describe with polar coordinates: is a polar function in which the length r is a function of the angle …but how to plot such a function…
Some curves are easier to describe with polar coordinates: is a polar function in which the length r is a function of the angle
Some curves are easier to describe with polar coordinates: is a polar function in which the length r is a function of the angle …but how can this be?
One way to give someone directions is to tell them to go three blocks East and five blocks South. Another way to give directions is to point and say “Go a half mile in that direction.” Polar graphing is like the second method of giving directions. Each point is determined by a distance and an angle. x-axis
One way to give someone directions is to tell them to go three blocks East and five blocks South. Another way to give directions is to point and say “Go a half mile in that direction.” Polar graphing is like the second method of giving directions. Each point is determined by a distance and an angle. But what about this coordinate pair? x-axis
Some curves are easier to describe with polar coordinates: is a polar function in which the length r is a function of the angle …but how can this be?
Some curves are easier to describe with polar coordinates: (Circle centered at the origin) (Try graphing it on your calculator) (Line through the origin whose slope is )
More than one coordinate pair can refer to the same point. All of the polar coordinates of this point are:
Tests for Symmetry: x-axis: If (r, q) is on the graph, so is (r, -q).
Tests for Symmetry: y-axis: If (r, q) is on the graph, so is (r, p-q) or (-r, -q).
Tests for Symmetry: origin: If (r, q) is on the graph, so is (-r, q) or (r, q+p) .
Tests for Symmetry: If a graph has two symmetries, then it has all three:
Converting to Cartesian Coordinates Remember the unit circle?
Converting to Cartesian Coordinates Convert to polar coordinates Graph this on your calculators for comparison