∞ ∫ 0 E − X D X

Question

\[\int\limits_0^\infty e^{- x} dx\]

Solution

\[Let\ I = \int_0^\infty e^{- x} d\ x\ . Then, \]
\[I = \left[ - e^{- x} \right]_0^\infty \]
\[ \Rightarrow I = - e^{- \infty} + e^0 \]
\[ \Rightarrow I = 0 + 1\]
\[ \Rightarrow I = 1\]

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Definite Integrals

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Q 8 Q 7 Q 9

Chapter 19: Definite Integrals - Exercise 20.1 [Page 16]

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R.D. Sharma Mathematics Volume 1 and 2 [English] Class 12

Chapter 19 Definite Integrals
Exercise 20.1 | Q 8 | Page 16

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