The value of the integral -11 ( x3+|x|+1x2+2|x|+1 )dx is equal to :
- 3 e 2
- 2 e 2
- 5 e 3
- 3 e 3
Answer
(2) 2 e 2
Solution
x2+2|x|+1=(|x|+1)2
I= -11 x3(|x|+1)2dx+ -11 |x|+1(|x|+1)2dx
The first integrand is odd its integral is 0
The second integrand 1|x|+1 is even
I=2 01 dxx+1=2 [ e(x+1) ]01
=2 e2
Answer: (2)