Question

Evaluate the integral:
dx / e^(pie*x) from 2 (upper bound) to 0.

Answer 1

\[\int\limits_{0}^{2}e ^{-pix}dx = -e ^{-2\pi}+1/\pi\]

Answer 2

Why is it that? Also, what happened to the X?

Answer 3

im looking at what Wolfram Alpha gave me, and their answer is (1/pi)e^(pi*x)

Answer 4

this is an definite integral, we have to evaluate this primitive.
You can make an substitution y = -pix and find this function

Answer 5

ahhh im only confusing myself.
I set u = -pi*x. du = -pi dx
So, integral of e^(-pi*x) becomes e^(u) * dx. Taking the integral of that is just e^(u)

Answer 6

yes. but excuse me I have a mistake evaluating function.
Don't forget the limits of integration

Answer 7

So it becomes:
e^(-pi*x) from 2 to 0? and that's the answer? (plug in 2 for the equation, and plug in 0 and subtract the two)?

Answer 8

Yes

Answer 9

okay thanks :)