Integrating Definite Integral: 3x^5 + 4x^4 + x^2

[noobie!]

there's a que which baffles me today,so i hope any1 of you could help me to clear my doubt,here is the que:

integrate with limit 3 on top n 1 below (3x^5 + 4x^4 + x^2)/x^3 dx ..
so here goes my sol please rectify me..
SOL: 3x^2 + 4x + x^-1
then integrate it
x^3 + 2x^2..<<<<then what about x^-1 ?if we integrate it the denominator will become infinite so any value + infinity it will become infinity?am i wright?pl help me,thanks a lot...

 

[Dr. Lady]

The integral of x^-1 is ln(x)... taken at the limits given, that's not infinity. You're method for solving is sound, but x^-1 is just one that you have to memorize.

 

[noobie!]

The integral of x^-1 is ln(x)... taken at the limits given, that's not infinity. You're method for solving is sound, but x^-1 is just one that you have to memorize.

thanks a lot,i didnt thought of that..thanks...