Now that's scary!

We tried teeth, we tried triangular eyes, but then I had an idea.
Lets put on the pumpkin something REALLY scary.
Now my original sketch had a trig. function in it too - but my carving isn't up to that and besides it would have gone around to the other side!

Just in case you can't read it it says
The integral of e to the power at dt.









and just in case you are curious, I think the solution is
1/a * e^(at) + C