Answer:
Step-by-step explanation:
First off, your written problem doesn't match the one you typed. The written problem doesn't have a solution, so I'm going with the typed one (cuz I can solve that one!).
Begin by noting that [tex]e^{-\frac{1}{2}[/tex] is a constant and can be pulled out front of the integration symbol:
[tex]e^{-\frac{1}{2}}\int\limits^\pi _0 {e^{-x}} \, dx[/tex]
Choose u = -x, so du/dx = -1 and -du = dx. Put that - out front along with what's already there to get:
[tex]-e^{-\frac{1}{2}}\int\limits^\pi _0 {e^{-u}} \, du[/tex]
The antiderivative of e^-u is e^-u, so putting it all together and applying the First Fundamental Theorem of Calculus:
[tex]-e^{-\frac{1}{2}}(e^{-\pi }-e^0)[/tex] which simplifies to
[tex]-e^{-\frac{1}{2}}(e^{-\pi }-1)[/tex] which simplifies to
[tex]-e^{-\pi -\frac{1}{2}}+e^{-\frac{1}{2}}[/tex] which has a decimal equivalency of .5803200934
