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By using the properties of the definite integral, evaluate the integral: ∫28|x-5|dx - Mathematics

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Question

By using the properties of the definite integral, evaluate the integral:

`int_2^8 |x - 5| dx`

Sum
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Solution

`int_2^8  abs (x - 5) dx`

Define,

`abs(x - 5) = {(-(x - 5), if x - 5 < 0, or x< 5),(x - 5, if x - 5 >= 0, or x >=5):}`

`= int_2^5  abs (x - 5)  dx + int_2^8  abs (x - 5)  dx`

`= - int_2^5  (x - 5)  dx + int_2^8  (x - 5)  dx`

`= - [x^2/2 - 5x]_2^5 + [x^2/2 - 5x]_5^8`

`= - [25/2 - 25 - 4/2 + 10]`

`= [64/2 - 4 - 25/2 + 25]`

`= - [(-9)/2] + [9/2]`

`= 9/2 + 9/2`

= 9

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Chapter 7: Integrals - Exercise 7.11 [Page 347]

APPEARS IN

NCERT Mathematics Part 1 and 2 [English] Class 12
Chapter 7 Integrals
Exercise 7.11 | Q 6 | Page 347

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