# Antiderivative of a function $f$

Can you help me to find which functions $F_1,\ldots,F_6$ are antiderivatives of $f$?

-
When is $f$ positive? When is $f$ negative? When does $f$ cross the $x$-axis? Yep, and what have you tried? –  FrenzY DT. Nov 26 '12 at 13:33
You should tag this as homework, as well as show some effort on your part. I imagine the lack of these is the source of the downvotes. –  Zach L. Nov 26 '12 at 13:35
This is not homework. –  Reader Nov 26 '12 at 13:36
Honest? This is NOT homework? Really? Because people will still help you, but if you tag the question as "homework" then all will know you must work by yourself problems and will give some good hints... –  DonAntonio Nov 26 '12 at 13:42
Is it correct that answer is $F_1, F_2$ and $F_6$ –  Reader Nov 26 '12 at 13:42
HINT: What does $f(x)\begin{cases}<0\\=0\\>0 \end{cases}$ mean for the antiderivative at the point $x$? And be careful, there might be more than one solution...