Test Index

NCERT Class XII Mathematics Chapter - - Solutions

Show Para  Hide Para 
Exercise - 7.6
Integrate the functions in Exercises 134 to 155.
© examsnet.com
Question : 150 of 271
Marks: +1, -0
xex(1+x)2\frac{x e^x}{(1+x)^2}
Solution:  
Let I=xex(1+x)2dxI = \frac{x e^x}{(1+x)^2} dx ⇒I=∫ex[1+x−1(1+x)2]dx\Rightarrow I = \int e^x \left[ \frac{1+x-1}{(1+x)^2} \right] dx
⇒I=∫ex[11+x−1(1+x)2]dx\Rightarrow I = \int e^x \left[ \frac{1}{1+x} - \frac{1}{(1+x)^2} \right] dx
⇒I=∫ex[11+x+(ddx(11+x))]dx\Rightarrow I = \int e^x \left[ \frac{1}{1+x} + \left( \frac{d}{dx} \left( \frac{1}{1+x} \right) \right) \right] dx
⇒I=[ex⋅11+x+C]\Rightarrow I = \left[ e^x \cdot \frac{1}{1+x} + C \right] [∵∫ex(f(x)+f′(x))dx=exf(x)+C]\left[ \because \int e^x (f(x)+f'(x)) dx = e^x f(x) + C \right]
© examsnet.com
Go to Question:
Advertisements