Question 1143134
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The derivative of tan(x) is  sec^2(x).


Therefore, the integral from  0  to  {{{pi/4}}}  of  {{{(sec^2(x)*e^(tan(x)))dx}}}, after substitution  u = tan(x) becomes


the integral from  0  to  1  of  {{{(e^u)*du}}}.


The last integral is  {{{e^1 - e^0}}} = e - 1.    <U>ANSWER</U>.


The <U>correct answer</U>  is  e-1.
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