4Integrating By parts
I = x eax /a ]∞0 - eax/a2 ]∞0
9 Answers
1ya but in dat case answer is cuming ∞.how is dat possible??
62see the integral will be inifinite simply becasue the function itself is gettting larger and larger with x...
If a is -ve then teh answer could be different.. (What do you think?? )
1ya obviously a has to be negative.let a=-b(b>0).then we put limits -∞ to 0.but then wat about xe-bx/bdx at x=-∞??
62Then the sign will reverse.
and the role of the sign willl get reversed....
Are you talking about the limit or the integral?
1i did it by integration by parts n then im putting ∞ in place of x but wat is da limiting value of -(xe-bx)/b at x=∞?
66As x→∞, if b > 0, then e-bx → 0 and since the exponential is much faster than any polynomial for large x, the quantity xe-bx → 0 as well. But this quantity grows without bound if b < 0.