Applications: Area, Volume & More

Area between curves, volumes of revolution, average value, and arc length.

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Applications: Area, Volume & More

12 questions

AP Learning Target(s): LT 1: Exploring Accumulations of Change, LT 7: The Fundamental Theorem of Calculus and Definite Integrals

Arc Length of a Curve

Which of the following integrals represents the length of the curve $$y = \sqrt{x}$$ on the interval $$[1, 4]$$?

  1. A.

    $$\displaystyle\int_{1}^{4} \sqrt{1 - \frac{1}{4x}} dx$$

  2. B.

    $$\displaystyle\int_{1}^{4} \sqrt{1 + \frac{1}{4}x^2} dx$$

  3. C.

    $$\displaystyle\int_{1}^{4} \sqrt{1 + \frac{1}{2\sqrt{x}}} dx$$

  4. D.

    $$\displaystyle\int_{1}^{4} \sqrt{1 + \frac{1}{4x}} dx$$

Correct answer: D
Area Calculation Using a Definite Integral

Which of the following is an example of correctly approximating the area under the curve $$f(x)=\sqrt{x}$$ from $$x=1$$ to $$x=4$$ using a definite integral?

  1. A.

    Area = $$4^{3/2}-1^{3/2}$$

  2. B.

    Area = $$\frac{2}{3}(4-1)=2$$

  3. C.

    Area = $$\frac{2}{3}(4^{3/2}-1^{3/2})=\frac{14}{3}$$

  4. D.

    Area = $$\frac{1}{2}(4^{3/2}-1^{3/2})$$

Correct answer: C
Area of a Reflected Region

Let R be the region in the first quadrant bounded by the graph of y = sin(x), the x-axis, and the line x = π/2. If the area of R is given by $\displaystyle\int_{0}$^(π/2) sin(x)dx = 1, what is the area of the region formed by reflecting R across the y-axis?

  1. A.

    2

  2. B.

    π/2

  3. C.

    1

  4. D.

    0

Correct answer: C
Area of a Region Between Two Curves

Let f and g be continuous functions such that f(x) ≥ g(x) on the interval [0, a]. If $\displaystyle\int_{0}$^a f(x)dx = 12 and $\displaystyle\int_{0}$^a g(x)dx = 5, what is the area of the region bounded by the graphs of f and g between x = 0 and x = a?

  1. A.

    17

  2. B.

    7

  3. C.

    60

  4. D.

    12 - 5a

Correct answer: B
Area Under a Curve

What is the area of the region enclosed by the graph of y = x², the x-axis, and the vertical lines x = 0 and x = 2?

  1. A.

    8.33

  2. B.

    1.5

  3. C.

    2.67

  4. D.

    4.16

Correct answer: C
Area Under a Linear Function

The accumulation of change of a linear function over an interval can be evaluated by finding the area of which geometric shape?

  1. A.

    Triangle

  2. B.

    Rectangle

  3. C.

    Circle

  4. D.

    Parabola

Correct answer: B
Average Value of a Function

The differentiable function $$h$$ models Tara's heart rate in beats per minute, where $$t$$ is the time in minutes since the start of a workout. Which of the following expressions gives Tara's average heart rate on the interval from $$t=30$$ to $$t=60$$?

  1. A.

    $$\frac{1}{30} \int_{30}^{60} h(t) dt$$

  2. B.

    $$\frac{h'(30) + h'(60)}{2}$$

  3. C.

    $$\int_{30}^{60} h(t) dt$$

  4. D.

    $$\frac{1}{30} \int_{30}^{60} h'(t) dt$$

Correct answer: A
Integral Expression for Bounded Area

The derivative of a function $$f$$ is given by $$f'(x) = x^3 - 6x^2 + 9x - 2$$. Which expression represents the area of the region enclosed by the graph of $$f'(x)$$ and the x-axis on the interval $$[0,3]$$?

  1. A.

    |f(3) - f(0)|

  2. B.

    $$\int_{0}^{3} |f'(x)| dx$$

  3. C.

    f(3) - f(0)

  4. D.

    f(3) + f(0)

Correct answer: B
Interpreting the Area Under a Curve

The area under the curve of a non-negative function represents which of the following?

  1. A.

    The average rate of change

  2. B.

    The maximum rate of change

  3. C.

    The instantaneous rate of change

  4. D.

    The accumulation of change

Correct answer: D
Volume by Shell Method

The region enclosed by the graphs of $$y = x^2$$ and $$y = 4$$ is revolved about the y-axis. Using the shell method, which of the following integrals gives the volume of the resulting solid?

  1. A.

    $\displaystyle\int_{0}^{4}$ π(2√y)² dy

  2. B.

    π$\displaystyle\int_{0}^{4}$ (2√y) dy

  3. C.

    $\displaystyle\int_{0}^{2}$ π[(4 - x²)² - x⁴] dx

  4. D.

    $\displaystyle\int_{0}^{2}$ 2πx(4 - x²) dx

Correct answer: D
Volume of a Solid of Revolution

What is the volume of the solid generated when the region enclosed by the graphs of $$y = x^2$$ and $$y = 4$$ is rotated about the y-axis?

  1. A.

    32π/3

  2. B.

    16π/3

  3. C.

    4π

  4. D.

    8π

Correct answer: D
Volume Using the Disk Method

The region bounded by the graph of $$y = \sqrt{x}$$, the x-axis, and the line $$x = 4$$ is revolved about the x-axis. Which of the following expressions represents the volume of the resulting solid as determined by the disk method?

  1. A.

    $$\int_{0}^{2} 2\pi y dy$$

  2. B.

    $$\int_{0}^{4} 2\pi x dx$$

  3. C.

    $$\int_{0}^{2} \pi y^2 dy$$

  4. D.

    $$\int_{0}^{4} \pi (\sqrt{x})^2 dx = \int_{0}^{4} \pi x dx$$

Correct answer: D