Math Problem Statement

Question content area top

Part 1

Find the area of the region described.

The region bounded by

yequals=StartAbsoluteValue x minus 3 EndAbsoluteValuex−3

and

yequals=StartFraction x Over 2 EndFractionx2

Question content area bottom

Part 1

The area of the region bounded by

yequals=StartAbsoluteValue x minus 3 EndAbsoluteValuex−3

and

yequals=StartFraction x Over 2 EndFractionx2

is

enter your response here.

​(Type an exact​ answer, using radicals as​ needed.)

Solution

To find the area of the region bounded by the two functions y=x3y = |x - 3| and y=x2y = \frac{x}{2}, we need to:

  1. Find the points of intersection between the two functions.
  2. Set up the integral(s) to calculate the area between these curves.
  3. Evaluate the integral(s).

Step 1: Find the Points of Intersection

The points of intersection occur where the two functions are equal:

x3=x2|x - 3| = \frac{x}{2}

This equation needs to be split into two cases, based on the definition of the absolute value.

Case 1: x30x - 3 \geq 0 (i.e., x3x \geq 3)

x3=x2x - 3 = \frac{x}{2}

Solve for xx:

2(x3)=x2(x - 3) = x

2x6=x2x - 6 = x

x=6x = 6

Case 2: x3<0x - 3 < 0 (i.e., x<3x < 3)

(x3)=x2-(x - 3) = \frac{x}{2}

2(x3)=x-2(x - 3) = x

2x+6=x-2x + 6 = x

3x=63x = 6

x=2x = 2

So, the points of intersection are x=2x = 2 and x=6x = 6.

Step 2: Set Up the Integral

The area between the curves is given by the integral of the difference between the upper and lower functions, from x=2x = 2 to x=6x = 6.

A=26[x3x2]dxA = \int_{2}^{6} \left[ |x - 3| - \frac{x}{2} \right] \, dx

We need to evaluate this integral in two parts, considering the definition of x3|x - 3|.

  • From x=2x = 2 to x=3x = 3, x3=(x3)=x+3|x - 3| = -(x - 3) = -x + 3.
  • From x=3x = 3 to x=6x = 6, x3=x3|x - 3| = x - 3.

So, we split the integral:

[ A = \int_{2}^{3} \left[ (-x + 3) - \frac{x}{2} \right] , dx + \int_{3}^{6} \left[ (x - 3) - \frac{x}{2} \right] , dx ]

Step 3: Evaluate the Integral

First Integral: 23[x+3x2]dx\int_{2}^{3} \left[ -x + 3 - \frac{x}{2} \right] \, dx

=23[3x2+3]dx= \int_{2}^{3} \left[ -\frac{3x}{2} + 3 \right] \, dx

=[34x2+3x]23= \left[ -\frac{3}{4}x^2 + 3x \right]_{2}^{3}

=(34(9)+9)(34(4)+6)= \left(-\frac{3}{4}(9) + 9 \right) - \left(-\frac{3}{4}(4) + 6 \right)

=(274+9)(3+6)= \left(-\frac{27}{4} + 9 \right) - \left(-3 + 6 \right)

=(274+364)3+6= \left(-\frac{27}{4} + \frac{36}{4} \right) - 3 + 6

=94+3=214= \frac{9}{4} + 3 = \frac{21}{4}

Second Integral: 36[x3x2]dx\int_{3}^{6} \left[ x - 3 - \frac{x}{2} \right] \, dx

=36[x23]dx= \int_{3}^{6} \left[ \frac{x}{2} - 3 \right] \, dx

=[14x23x]36= \left[ \frac{1}{4}x^2 - 3x \right]_{3}^{6}

=(14(36)18)(14(9)9)= \left(\frac{1}{4}(36) - 18 \right) - \left(\frac{1}{4}(9) - 9 \right)

=(918)(949)= \left(9 - 18 \right) - \left(\frac{9}{4} - 9 \right)

=9274+364= -9 - \frac{27}{4} + \frac{36}{4}

=9+94=274= -9 + \frac{9}{4} = \frac{-27}{4}

Combine the Results

A=214+274=484=12A = \frac{21}{4} + \frac{27}{4} = \frac{48}{4} = 12

So, the exact area of the region is 12\boxed{12}.

Do you have any questions or need further details on any of these steps?


5 Related Questions:

  1. How would you find the area if the functions were different?
  2. What happens if one of the functions is non-linear, such as a quadratic function?
  3. How would the procedure change if the bounds were not the x-axis but y-axis?
  4. Can you find the area between two curves using polar coordinates?
  5. How can you determine the intersection points for more complex functions?

Tip: Always check the domain where the functions intersect to ensure the correct setup of integrals.

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Math Problem Analysis

Mathematical Concepts

Absolute Value Functions
Integration

Formulas

Integral of absolute value function

Theorems

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Suitable Grade Level

Grades 11-12