# Thread: Antiderivative of an Exponential

1. ## Antiderivative of an Exponential

Hi all,

I know that $\int1/e^{\frac{1}{2}y}dy=-2e^{\frac{-y}{2}}$

but I don't know how it's done?

I can integrate the denominator to get $2e^{\frac{1}{2}y}$

but since it's under the "1" I've not seen this before, what rules does it use?

Many thanks.

2. ## re: Antiderivative of an Exponential

$\displaystyle \frac{1}{e^{\frac{1}{2}y}} = e^{\frac{-y}{2}}$

3. ## re: Antiderivative of an Exponential

Many thanks, once again my rules for powers have let me down.