Parametric, Polar & Vector-Valued Functions unit test
A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.
Finding the limits for a polar area
Vector-valued position
Second derivative parametrically
Area between polar curves
Displacement versus distance
Petal width
Common polar curves
Area in polar coordinates
Vertical and horizontal tangents parametrically
Polar intersections can miss the pole
Parametric derivative
Parametric equations describe motion, not just a curve
Short answer 1. Define or explain: Finding position from velocity
3 ptsShort answer 2. Define or explain: Area between two polar curves
3 ptsShort answer 3. Define or explain: Speed in the plane
3 ptsShort answer 4. Define or explain: Speeding up in the plane
3 ptsFree response
9 ptsCALCULATOR PERMITTED. Curve C is defined by the polar equation r(θ) = 2 sin²θ for 0 ≤ θ ≤ π. Curve C and the semicircle r = 1/2 (also for 0 ≤ θ ≤ π) are shown in the xy-plane: C is a large oval-shaped loop reaching up to about y = 2.1, and the small semicircle of radius 1/2 sits over the origin, crossing C near θ = π/6 and θ = 5π/6. (Your calculator should be in radian mode.)
A. Find the rate of change of r with respect to θ at the point on curve C where θ = 1.3. Show the setup for your calculations.
B. Find the area of the region that lies inside curve C but outside the graph of the polar equation r = 1/2. Show the setup for your calculations.
C. It can be shown that dx/dθ = 4 sin θ cos²θ − 2 sin³θ for curve C. For 0 ≤ θ ≤ π/2, find the value of θ that corresponds to the point on curve C that is farthest from the y-axis. Justify your answer.
D. A particle travels along curve C so that dθ/dt = 15 for all times t. Find the rate at which the particle’s distance from the origin changes with respect to time when the particle is at the point where θ = 1.3. Show the setup for your calculations.