Cogito
AP Calculus BC · Chapter 2 · Lesson 1
Polar Coordinates
Locating a point by distance and angle.
11 problems · about 24 minutes · AP Calculus BC 9.7, 9.8
Figure — use these to answer the problems
- Angle60° = π/3 rad
- x-coordinate0.500
- y-coordinate0.866
- cos 60°0.500
- sin 60°0.866
Warm Up
Straightforward practice. Get the method working first.
4 problemsCartesian (6, 8). What is r?
Answerr = 3, θ = 0°. What is y?
Answerr = 4, θ = 90°. What is y?
AnswerCartesian (3, 4). What is r?
Answer
Build It Up
The same ideas with more to keep track of.
3 problemsCartesian (0, 7). What is r?
Answerr = 6, θ = 180°. What is x?
AnswerSet the angle to 270°, where cosine is 0 and sine is −1.
Set the model in the app, then write the values you used.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
4 problemsDoes adding 360° to θ change the point? 1 for yes, 0 for no.
AnswerCartesian (0, 0). What is r?
AnswerStraight Out
r = 5, θ = 0°. What is x?
AnswerStraight Up
r = 5, θ = 90°. What is x?
Answer