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The graph of a function f is shown above. What is the value of
\int\limits^7_0 {f(x)} \, dx

The graph of a function f is shown above. What is the value of \int\limits^7_0 {f-example-1
User Yorammi
by
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1 Answer

9 votes

Answer: 6

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Step-by-step explanation:

Split the graph into separate regions (see the diagram below)

The red trapezoid has the parallel vertical sides of b1 = 1 and b2 = 2. The height of the trapezoid is h = 2

The area of the red trapezoid is

A = h*(b1+b2)/2 = 2*(1+2)/2 = 3

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The blue rectangle has a horizontal side of 2 and vertical side of 2. Its area is 2*2 = 4 square units.

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The pink triangle has a base of 1 and height of 2

area = base*height/2 = 1*2/2 = 1 square unit

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The green triangle has an area of base*height/2 = 2*2/2 = 2 square units

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For any region above the x axis, it gets assigned a positive area. Anything below the x axis gets a negative area to counterbalance the positive areas.

The regions above the x axis add to 3+4+1 = 8 square units. Then we subtract off the area of the green triangle to get 8-2 = 6 square units.

Therefore,
\displaystyle \int_(0)^(7)f(x)dx = 6

The graph of a function f is shown above. What is the value of \int\limits^7_0 {f-example-1
User Hiadore
by
3.2k points