ANTIDERIVATIVE

[Ryan Rigdon]

My problem

Find an antiderivative for the function f(x) = x^2 + e when C = 0.

My work

integral (x^2 + e) dx

integral x^2 dx + e integral 1 dx

(x^3)/3 + ex + C

when C = 0

Our antiderivative for this problem is

(x^3)/3 + ex

Look good?

 

[tkhunny]

I suppose, but this [e integral 1] seems a little silly. Are you sure it wasn't \(\displaystyle e^x\)?

 

[Ryan Rigdon]

i know it seems weird but thats the way it looked on my assignment. i did another problem just like it, except the e was a ?. which we all know that both are constants.

 

[tkhunny]

Fair enough. Some teachers insist that you pull out all constants. There really is no need for that. Anyway, I would suggest doing it however it will be judged correct on your exams.

 

[Deleted member 4993]

i know it seems weird but thats the way it looked on my assignment. i did another problem just like it, except the e was a ?. which we all know that both are constants.

The confusion arises from the fact that where as e(x) or e[sup:2q710qdl]x[/sup:2q710qdl] is a very common function ?[sup:2q710qdl]x[/sup:2q710qdl] is not. Just to avoid confusion - in this case it would be prudent to write x*e (instead of ex).

 

[Ryan Rigdon]

i agree. but in this case e was just a constant like we all know. but if we were dealing with e^x then we would have to take the ln of it wouldnt we?

 

[tkhunny]

Part of the art of mathematics is communicating clearly. "ex" is a little awkward, and possibly will be misunderstood. There is no significant argument that suggests only "was just...like we all know". We will NOT "all know" by next week and it will be confusing all over again. May as well write it as clearly as possible the first time and we will forever be unconfused.