The value of x 0 e ( (ex) (e2x) (e10x) )e2 - e2 x is equal to
- (e10 - 1)2e2(e2 - 1)
- (e20 - 1)2e2(e2 - 1)
- (e10 - 1)2(e2 - 1)
- (e20 - 1)2(e2 - 1)
Answer
(4) (e20 - 1)2(e2 - 1)
Solution
Numerator N = k=110 e (ek x) = - k=110 e (ek x)
0 - e 2 = 0 1 - 2 = 12
x 0 Nx2 = 12 k=110 e2k = 12 e2(e20 - 1)e2 - 1
Denominator = e2 - e2 x = -e2 (e2 x - 2 - 1 )
2 x - 2 = -4 2 x2 0 and et - 1t 1
x 0 e2 - e2 xx2 = -e2 x 0 2 x - 2x2 = -e2(-1) = e2
Limit = e2(e20 - 1)2(e2 - 1) 1e2
= (e20 - 1)2(e2 - 1)
Answer: (4)