If - 2 2 96x2 2 x(1 + ex) dx = ( 2 + ), , Z, then ( + )2 equals
- 196
- 100
- 64
- 144
Answer
(2) 100
Solution
Let I = - 2 2 96x2 2 x1 + ex dx. Using x -x:
I = - 2 2 96x2 2 x ex1 + ex dx
Adding: 2I = - 2 2 96x2 2 x dx = 2 0 2 96x2 2 x dx
I = 48 0 2 x2(1 + 2x) dx
0 2 x2 dx = 324
x2 2x dx = x2 2x2 + x 2x2 - 2x4
0 2 x2 2x dx = 2 (-1)2 = - 4
I = 48 ( 324 - 4 ) = 2 3 - 12 = (2 2 - 12)
= 2, = -12
( + )2 = (-10)2 = 100
Answer: (2)