Update articles/data-factory/data-flow-expression-functions.md

Co-Authored-By: Jason Roth <[email protected]>

Author: V-vafune

articles/data-factory/data-flow-expression-functions.md

@@ -432,7 +432,7 @@ Finds the position(1 based) of the substring within a string starting a certain
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 ### <code>log</code>
 <code><b>log(<i>&lt;value1&gt;</i> : number, [<i>&lt;value2&gt;</i> : number]) => double</b></code><br/><br/>
-Calculates log value. An optional base can be supplied else a euler number if used
+Calculates log value. An optional base can be supplied else a Euler number if used
 * ``log(100, 10) -> 2``  
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 ### <code>log10</code>