1. Chapter 7 Class 12 Integrals (Term 2)
  2. Serial order wise
  3. Miscellaneous

Misc 35 - Chapter 7 Class 12 Integrals (Term 2)

Last updated at Dec. 23, 2019 by

Misc 35 - Prove definite integral 0->1 x ex dx = 1 - Miscellaneous

Misc 35 - Chapter 7 Class 12 Integrals - Part 2

  1. Chapter 7 Class 12 Integrals (Term 2)
  2. Serial order wise

    3. Miscellaneous

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Transcript

Misc 35 Prove that โˆซ_0^1โ–’๐‘ฅ ๐‘’^๐‘ฅ ๐‘‘๐‘ฅ=1 Solving L.H.S โˆซ_0^1โ–’๐‘ฅ ๐‘’^๐‘ฅ ๐‘‘๐‘ฅ First we will solve โˆซ1โ–’๐’™ ๐’†^๐’™ ๐’…๐’™ โˆซ1โ–’๐‘ฅ ๐‘’^๐‘ฅ ๐‘‘๐‘ฅ Now we know that โˆซ1โ–’ใ€–๐‘“(๐‘ฅ) ๐‘”โก(๐‘ฅ) ใ€— ๐‘‘๐‘ฅ=๐‘“(๐‘ฅ) โˆซ1โ–’๐‘”(๐‘ฅ) ๐‘‘๐‘ฅโˆ’โˆซ1โ–’(๐‘“^โ€ฒ (๐‘ฅ) โˆซ1โ–’๐‘”(๐‘ฅ) ๐‘‘๐‘ฅ) ๐‘‘๐‘ฅ Putting value of f(x) = x and g(x) = ex โˆซ1โ–’๐‘ฅ ๐‘’^๐‘ฅ ๐‘‘๐‘ฅ=๐‘ฅโˆซ1โ–’ใ€–๐‘’^๐‘ฅ ๐‘‘๐‘ฅใ€—โˆ’โˆซ1โ–’(๐‘‘๐‘ฅ/๐‘‘๐‘ฅ โˆซ1โ–’ใ€–๐‘’^๐‘ฅ ๐‘‘๐‘ฅใ€—) ๐‘‘๐‘ฅ = ๐‘ฅ๐‘’^๐‘ฅโˆ’โˆซ1โ–’1. ๐‘’^๐‘ฅ ๐‘‘๐‘ฅ = ๐‘ฅ๐‘’^๐‘ฅโˆ’๐‘’^๐‘ฅ+๐ถ Applying limits โˆซ1_0^1โ–’ใ€–๐‘ฅ ๐‘’^๐‘ฅ ๐‘‘๐‘ฅใ€— = [๐‘ฅ๐‘’^๐‘ฅโˆ’๐‘’^๐‘ฅ ]_0^1 = (1๐‘’^1โˆ’๐‘’^1 )โˆ’(0.๐‘’^0โˆ’๐‘’^0) = (๐‘’^1โˆ’๐‘’^1 )โˆ’ (0 โˆ’ 1) = 1 = R.H.S Hence proved.

Chapter 7 Class 12 Integrals (Term 2)
Serial order wise

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.