The value of the integral - /4 /4 ( 32 4 x1+e x )dx is :
- 4 +2
- 3 +8
- 3 +4
- 4 +3
Answer
(2) 3 +8
Solution
I= - /4 /4 32 4 x1+e xdx
Replacing x by -x : I= - /4 /4 32 4 x1+e- xdx= - /4 /4 32 4 x e x1+e xdx
Adding : 2I= - /4 /432 4 x dx=2 0 /432 4 x dx (even function)
I= 0 /432 4 x dx
32 4 x=8(1+ 2x)2=8 (1+2 2x+ 1+ 4x2 )=12+16 2x+4 4x
I= [12x+8 2x+ 4x ]0 /4
=3 +8+0=3 +8
Answer: (2)