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Ch. 6 - Applications of Integration
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Not the one you use?Change textbook
Chapter 6, Problem 6.R.35

35-38. Area and volume Let R be the region in the first quadrant bounded by the graph of
Piecewise function f(x) equals 1 for x between 0 and 1, and 2 minus square root of x for x between 1 and 4.
Find the area of the region R.

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Identify the region R in the first quadrant bounded by the piecewise function \( f(x) \) and the x-axis. The function is given by: \[ f(x) = \begin{cases} 1 & \text{if } 0 \leq x \leq 1 \\ 2 - \sqrt{x} & \text{if } 1 < x \leq 4 \end{cases} \] This means the region is bounded above by \( f(x) \) and below by the x-axis from \( x=0 \) to \( x=4 \).
To find the area of region R, set up the integral of \( f(x) \) over the interval \( [0,4] \). Since \( f(x) \) is piecewise, split the integral into two parts: \[ \text{Area} = \int_0^1 1 \, dx + \int_1^4 (2 - \sqrt{x}) \, dx \]
Evaluate the first integral: \[ \int_0^1 1 \, dx = [x]_0^1 = 1 - 0 \] This represents the area of the rectangle under \( f(x) = 1 \) from 0 to 1.
For the second integral, rewrite the integrand and integrate term-by-term: \[ \int_1^4 (2 - \sqrt{x}) \, dx = \int_1^4 2 \, dx - \int_1^4 x^{1/2} \, dx \] Calculate each integral separately using the power rule for integration.
After finding the antiderivatives, apply the Fundamental Theorem of Calculus by evaluating the definite integrals at the limits \( x=1 \) and \( x=4 \). Then, sum the results of both integrals to get the total area of region R.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

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