How do you evaluate the integral #int 1/x# from [0,1]?

2 Answers
Feb 20, 2018

It's undefined.

Explanation:

The integral #int_0^1 1/xdx# is equivalent to #int_0^1x^-1dx#.
All integrals of the form #int_0^t x^ndx#, where #t# is a real parameter, are equal to #t^(n+1)/(n+1)#, so if #t = 1# and #n=-1#,
#int_0^1 1/xdx# = #1^0/0#, which is undefined.

Feb 20, 2018

Diverging...

Explanation:

#int_0 ^1 1/x dx = [ln(x) ]_0 ^1 #

#=> ln1 - ln0 = ln 0 #

We know #ln0# is undefined, but #lim_(n to 0^+ ) ln n = -oo#

So hence the integral is diverging...