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∫14∣x−2∣dx\int_1^4 |x - 2|dx is equal to

Solution

✅ Correct Option: 4

The absolute value ∣x−2∣|x - 2| changes behavior at x=2x = 2.

When x<2x < 2: (x−2)(x - 2) is negative, so ∣x−2∣=−(x−2)=2−x|x - 2| = -(x - 2) = 2 - x

When x≥2x \geq 2: (x−2)(x - 2) is positive, so ∣x−2∣=x−2|x - 2| = x - 2


Since the limits go from 1 to 4, and the behavior changes at x=2x = 2:

∫14∣x−2∣dx=∫12∣x−2∣dx+∫24∣x−2∣dx\int_1^4 |x - 2|dx = \int_1^2 |x - 2|dx + \int_2^4 |x - 2|dx

=∫12(2−x)dx+∫24(x−2)dx= \int_1^2 (2 - x)dx + \int_2^4 (x - 2)dx


For the first integral:

∫12(2−x)dx=[2x−x22]12\int_1^2 (2 - x)dx = \left[2x - \frac{x^2}{2}\right]_1^2

=(2(2)−42)−(2(1)−12)= \left(2(2) - \frac{4}{2}\right) - \left(2(1) - \frac{1}{2}\right)

=(4−2)−(2−0.5)= (4 - 2) - (2 - 0.5)

=2−1.5= 2 - 1.5

=12= \frac{1}{2}


For the second integral:

∫24(x−2)dx=[x22−2x]24\int_2^4 (x - 2)dx = \left[\frac{x^2}{2} - 2x\right]_2^4

=(162−8)−(42−4)= \left(\frac{16}{2} - 8\right) - \left(\frac{4}{2} - 4\right)

=(8−8)−(2−4)= (8 - 8) - (2 - 4)

=0−(−2)= 0 - (-2)

=2= 2


Adding both parts:

∫14∣x−2∣dx=12+2\int_1^4 |x - 2|dx = \frac{1}{2} + 2

=12+42= \frac{1}{2} + \frac{4}{2}

=52= \frac{5}{2}

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