Evaluate ∫_(-1)^2|x^3-3x^2+2x|  dx

This question is similar to Question 30 - CBSE Class 12 Sample Paper 2020 Boards

[Class 12] Evaluate Integal: ∫ |x^3 - 3x^2 + 2x| dx from -1 to 2 - CBSE Class 12 Sample Paper for 2022 Boards (For Term 2)

part 2 - Question 11 - CBSE Class 12 Sample Paper for 2022 Boards (For Term 2) - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards - Class 12
part 3 - Question 11 - CBSE Class 12 Sample Paper for 2022 Boards (For Term 2) - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards - Class 12
part 4 - Question 11 - CBSE Class 12 Sample Paper for 2022 Boards (For Term 2) - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards - Class 12

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Question 11 Evaluate ∫_(−1)^2▒|𝑥^3−3𝑥^2+2𝑥| dx |𝒙^𝟑−𝟑𝒙^𝟐+𝟐𝒙|=|𝑥(𝑥^2−3𝑥+2)| =|𝑥(𝑥^2−2𝑥−𝑥+2)| =|𝑥(𝑥(𝑥−2)−1(𝑥−2)) | =|𝒙(𝒙−𝟏)(𝒙−𝟐)| Thus, 𝑥=0,𝑥=1,𝑥=2 ∴ |𝒙^𝟑−𝟑𝒙^𝟐+𝟐𝒙|={█(−𝑥 . −(𝑥−1) . −(𝑥−2) 𝑖𝑓 −1≤𝑥<0@𝑥 . −(𝑥−1) . −(𝑥−2) 𝑖𝑓 0≤𝑥<1@𝑥 . (𝑥−1) . −(𝑥−2) 𝑖𝑓 1≤𝑥<2)┤ ={█(−𝑥(𝑥−1) (𝑥−2) 𝑖𝑓 −1≤𝑥<0@𝑥(𝑥−1)(𝑥−2) 𝑖𝑓 0≤𝑥<1@−𝑥(𝑥−1)(𝑥−2) 𝑖𝑓 1≤𝑥<2)┤ ={█(−(𝒙^𝟑−𝟑𝒙^𝟐+𝟐𝒙) 𝑖𝑓 −1≤𝑥<0@(𝒙^𝟑−𝟑𝒙^𝟐+𝟐𝒙) 𝑖𝑓 0≤𝑥<1@−(𝒙^𝟑−𝟑𝒙^𝟐+𝟐𝒙) 𝑖𝑓 1≤𝑥<2)┤ Now, ∫_(−𝟏)^𝟐▒|𝒙^𝟑−𝟑𝒙^𝟐+𝟐𝒙| dx = ∫_(−1)^0▒〖−(𝑥^3−3𝑥^2+2𝑥)〗 𝑑𝑥+∫_0^1▒〖(𝑥^3−3𝑥^2+2𝑥)〗 𝑑𝑥 +∫_1^2▒〖−(𝑥^3−3𝑥^2+2𝑥)〗 𝑑𝑥 = −[𝑥^4/4−3 ×𝑥^3/3+2 ×𝑥^2/2]_(−1)^0+[𝑥^4/4−3 ×𝑥^3/3+2 ×𝑥^2/2]_0^1 ` −[𝑥^4/4−3 ×𝑥^3/3+2 ×𝑥^2/2]_1^2 = −[𝒙^𝟒/𝟒−𝒙^𝟑+𝒙^𝟐 ]_(−𝟏)^𝟎+[𝒙^𝟒/𝟒−𝒙^𝟑+𝒙^𝟐 ]_𝟎^𝟏−[𝒙^𝟒/𝟒−𝒙^𝟑+𝒙^𝟐 ]_𝟏^𝟐 = −[((0^4 )/4−0^3+0^2 )−((−1)^4/4−(−1)^3+(−1)^2 )] +[(1^4/4−1^3+1^2 )−((0^4 )/4−0^3+0^2 )] −[(2^4/4−2^3+2^2 )−(1^4/4−1^3+1^2 )]= −[0−(1/4+1+1)] +[(1/4−1+1)−0] −[(4−8+4)−(1/4−1+1)] = −[−9/4]+[1/4]−[0−1/4] = 9/4+1/4+1/4 = 𝟏𝟏/𝟒

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo