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  1. AP Calculus
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What is the formula for the area of a region bounded by a single polar curve?

A=12∫abr2dθA = \frac{1}{2} \int_a^b r^2 d\thetaA=21​∫ab​r2dθ

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What is the formula for the area of a region bounded by a single polar curve?

A=12∫abr2dθA = \frac{1}{2} \int_a^b r^2 d\thetaA=21​∫ab​r2dθ

What is the formula for the area of a region bounded by two polar curves?

A=12∫ab(r22−r12)dθA = \frac{1}{2} \int_a^b (r_2^2 - r_1^2) d\thetaA=21​∫ab​(r22​−r12​)dθ, where r2r_2r2​ is the outer radius and r1r_1r1​ is the inner radius.

How do you find the area between two polar curves?

A=12∫αβ[f(θ)2−g(θ)2]dθA = \frac{1}{2} \int_{\alpha}^{\beta} [f(\theta)^2 - g(\theta)^2] d\thetaA=21​∫αβ​[f(θ)2−g(θ)2]dθ, where f(θ)f(\theta)f(θ) is the outer curve and g(θ)g(\theta)g(θ) is the inner curve.

What is a polar curve?

A curve defined using polar coordinates (r,θ)(r, \theta)(r,θ), where rrr is the distance from the origin and θ\thetaθ is the angle from the positive x-axis.

Define polar coordinates.

A two-dimensional coordinate system where each point is determined by a distance rrr from a reference point (the pole) and an angle θ\thetaθ from a reference direction (the polar axis).

What does rrr represent in polar coordinates?

rrr represents the radial distance from the origin to the point in the polar coordinate system.

What does θ\thetaθ represent in polar coordinates?

θ\thetaθ represents the angle measured counterclockwise from the positive x-axis to the line segment connecting the origin to the point.

How do you find the intersection points of two polar curves?

Set the two polar equations equal to each other, r1(θ)=r2(θ)r_1(\theta) = r_2(\theta)r1​(θ)=r2​(θ), and solve for θ\thetaθ. These θ\thetaθ values are the angles at the intersection points.

Outline the steps to find the area between r=3r = 3r=3 and r=3−2sin⁡(2θ)r = 3 - 2\sin(2\theta)r=3−2sin(2θ) in the second quadrant.

  1. Identify r1=3r_1 = 3r1​=3 and r2=3−2sin⁡(2θ)r_2 = 3 - 2\sin(2\theta)r2​=3−2sin(2θ). 2. Determine bounds: π2\frac{\pi}{2}2π​ to π\piπ. 3. Set up the integral: A=12∫π2π[(3−2sin⁡(2θ))2−32]dθA = \frac{1}{2} \int_{\frac{\pi}{2}}^{\pi} [(3 - 2\sin(2\theta))^2 - 3^2] d\thetaA=21​∫2π​π​[(3−2sin(2θ))2−32]dθ. 4. Evaluate the integral.

How do you determine which polar function is the 'inner' function?

Imagine yourself at the origin. The function you see first is the inner function.