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I am trying to write down the following expression
Integrate[Exp[-a/2/x]/x/(x + 1), {x, 0, b}, Assumptions -> a > 0 && b > 0]
using mathematical notation. I have tried
Assuming[b > 0 && a > 0, Subscript[\[Integral], 0]^b E^(-(a/(2 x)))/(x (x + 1)) \[DifferentialD]x]
and in picture
However, Mathematica returns Syntax: Incomplete expression; more input is needed.
Could you please give guidance what is wrong here? Thank you.
There is a syntax error with Subscript
Try
Assuming[b > 0 && a > 0, Integrate[Exp[-a/2/x]/x/(x + 1), {x, 0, b}]]
(*-E^(a/2) ExpIntegralEi[-((a (1 + b))/(2 b))]*)
Integrate[Exp[-a/2/x]/x/(x + 1), {x, 0, b}, Assumptions -> a > 0 && b > 0] and the screenshot should be equivalent and the former evaluates fine but the latter does not evaluate. The Subscript line is just a copy-paste of the screenshot from the Mathematica editor; I did not enter that. What is wrong in the screenshot? Do I write the integral incorrectly?
$\endgroup$
Integrate, Subscript should be used to enter $x_{min}$, the lower boundary of the integral, when using "nice notation" (my terminology).
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I found the issue. The solution was in the examples section of Integrate. The syntax error is with the superscript ^ after \[Integral] in Subscript[\[Integral], 0]^b. Ctrl+% has to be used instead of Ctrl+^.
Correctly:
Assuming[b > 0 && a > 0, \!\(\*SubsuperscriptBox[\(\[Integral]\), \(0\), \(b\)]\(\*FractionBox[SuperscriptBox[\(E\), \(-\*FractionBox[\(a\), \(2 x\)]\)], \(x \((x + 1)\)\)] \[DifferentialD]x\)\)]
This looks long here but copying it back to the Mathematica editor results again in the nice picture posted in the question.