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Evaluate : int(2)^(5)[|x-2|+|x-3|+|x-4...

Evaluate :
`int_(2)^(5)[|x-2|+|x-3|+|x-4|]dx`

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The correct Answer is:
To evaluate the integral \[ I = \int_{2}^{5} \left( |x-2| + |x-3| + |x-4| \right) dx, \] we will break it down into simpler parts by considering the behavior of the absolute value functions within the limits of integration. ### Step 1: Identify the points of interest The expressions inside the absolute values change at \(x = 2\), \(x = 3\), and \(x = 4\). We will evaluate the integral in segments based on these points. ### Step 2: Break the integral into segments We can break the integral into three parts: 1. From \(2\) to \(3\) 2. From \(3\) to \(4\) 3. From \(4\) to \(5\) Thus, we can write: \[ I = \int_{2}^{3} (|x-2| + |x-3| + |x-4|) dx + \int_{3}^{4} (|x-2| + |x-3| + |x-4|) dx + \int_{4}^{5} (|x-2| + |x-3| + |x-4|) dx \] ### Step 3: Evaluate each segment #### Segment 1: \(x \in [2, 3]\) In this interval: - \( |x-2| = x-2 \) - \( |x-3| = 3-x \) - \( |x-4| = 4-x \) Thus, \[ \int_{2}^{3} (|x-2| + |x-3| + |x-4|) dx = \int_{2}^{3} \left( (x-2) + (3-x) + (4-x) \right) dx \] Simplifying the integrand: \[ = \int_{2}^{3} (5 - 2x) dx \] Now, we calculate the integral: \[ = \left[ 5x - x^2 \right]_{2}^{3} = \left( 5(3) - (3)^2 \right) - \left( 5(2) - (2)^2 \right) \] \[ = (15 - 9) - (10 - 4) = 6 - 6 = 0 \] #### Segment 2: \(x \in [3, 4]\) In this interval: - \( |x-2| = x-2 \) - \( |x-3| = x-3 \) - \( |x-4| = 4-x \) Thus, \[ \int_{3}^{4} (|x-2| + |x-3| + |x-4|) dx = \int_{3}^{4} \left( (x-2) + (x-3) + (4-x) \right) dx \] Simplifying the integrand: \[ = \int_{3}^{4} (x - 1) dx \] Now, we calculate the integral: \[ = \left[ \frac{x^2}{2} - x \right]_{3}^{4} = \left( \frac{(4)^2}{2} - 4 \right) - \left( \frac{(3)^2}{2} - 3 \right) \] \[ = \left( 8 - 4 \right) - \left( \frac{9}{2} - 3 \right) = 4 - \left( \frac{9}{2} - \frac{6}{2} \right) = 4 - \frac{3}{2} = \frac{8}{2} - \frac{3}{2} = \frac{5}{2} \] #### Segment 3: \(x \in [4, 5]\) In this interval: - \( |x-2| = x-2 \) - \( |x-3| = x-3 \) - \( |x-4| = x-4 \) Thus, \[ \int_{4}^{5} (|x-2| + |x-3| + |x-4|) dx = \int_{4}^{5} \left( (x-2) + (x-3) + (x-4) \right) dx \] Simplifying the integrand: \[ = \int_{4}^{5} (3x - 9) dx \] Now, we calculate the integral: \[ = \left[ \frac{3x^2}{2} - 9x \right]_{4}^{5} = \left( \frac{3(5)^2}{2} - 9(5) \right) - \left( \frac{3(4)^2}{2} - 9(4) \right) \] \[ = \left( \frac{75}{2} - 45 \right) - \left( \frac{48}{2} - 36 \right) = \left( \frac{75}{2} - \frac{90}{2} \right) - \left( \frac{48}{2} - \frac{72}{2} \right) \] \[ = \left( -\frac{15}{2} \right) - \left( -\frac{24}{2} \right) = -\frac{15}{2} + \frac{24}{2} = \frac{9}{2} \] ### Step 4: Combine the results Now, we combine the results from all segments: \[ I = 0 + \frac{5}{2} + \frac{9}{2} = \frac{14}{2} = 7 \] ### Final Answer Thus, the value of the integral is: \[ \boxed{7} \]
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