AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
POLAR COORDINATES
To form the polar coordinate system in the plane, fix a point O, called the pole (or origin), and construct from O an initial ray called the polar axis, as shown in the figure.
Then each point P in the plane can be assigned polar coordinates r, , as follows.
rOP directed distance from to
directed angle, counter clockwise from polar axis to OP
With rectangular coordinates, each point x, y has a unique representation. This is not true with polar coordinates. For instance, the coordinates r, and r,2 represent the same point. Also because r is a directed distance, the coordinates r, and r, represent the same point. AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
COORDINATES CONVERSION
To establish the relationship between polar and rectangular coordinates , let the polar axis to coincide with the positive x-axis and the pole with the origin.
y tan x
x y cos , and sin r r
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
Sample Problem #1:
Convert each of the following points into the given coordinate system.
2 a) 4, into Cartesian coordinates 3 b) 1, 1 into Polar coordinates
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
Sample Problem #2:
Convert each of the following into an equation in the given coordinate system.
3 a) Convert 25x xxy 1 into polar coordinates.
b) Convert r 8cos into Cartesian coordinates.
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
COMMON POLAR GRAPHS
LINES: Some lines have fairly simple equations in polar coordinates.
1.
2. racos
3. rbsin
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
Sample Problem #3: USE YOUR POLAR COORDINATE GRAPH PAPER
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
CIRCLES:
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
Sample Problem #4: USE YOUR POLAR COORDINATE GRAPH PAPER
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
CARDIOIDS and LIMACONS:
Sample Problem #5: USE YOUR POLAR COORDINATE GRAPH PAPER
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
TANGENTS WITH POLAR COORDINATES
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
Sample Problem #5:
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
AREA WITH POLAR COORDINATES
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
Sample Problem #6:
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
Sample Problem #7:
Sample Problem #8:
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
Sample Problem #9:
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
ARC LENGTH WITH POLAR COORDINATES
The arc length formula for polar coordinates is:
Sample Problem #10:
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
SURFACE AREA WITH POLAR COORDINATES
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
HOMEWORK:
SECTION 1:
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729
SECTION 2:
AP CALCULUS BC Section 10.4: POLAR COORDINATES AND POLAR GRAPHS, pg. 729