1.

Let a and b be two positive real numbers. Then the value of `int_(a)^(b)(e^(x//a)-e^(b//x))/(x)dx` is

Answer» Correct Answer - A
`I=int_(a)^(b)(e^(x//a)-e^(b//a))/(x)dx`
Put `(x)/(a)=(b)/(y)`
`rArr" "I=int_(b)^(a)(e^((b)/(y))-e^((y)/(a)))/((ab)/(y))(-(ab)/(y^(2)))dy`
`" "=int_(a)^(b)(b^(b//x)-e^(x//a))/(x)dx=-I`
`rArr" "2I=0`
`rArr" "I=0`


Discussion

No Comment Found