Hello,

I would like to plot a vertical line each time my function is null and is increasing.

Here an extract of my code:

**v:=unapply(H*sin(w*t),t);**

**L:=0.080;**

**H:=0.020;**

**Vf:=0.3;**

**w:=10;**

**fsolve(v(t)=0,t=0.5..2);**

**zeros:=Roots(v(t),t=0.5..2);**

**vdot:=unapply(diff(v(t),t),t);**

**map(vdot,zeros);**

**LignesVerticales=implicitplot(x=***To complete***, colour=yellow,linestyle=3, thickness=2):**

With **Roots **function, I could obtain the zero-crossings.

With the derative of the functions, I could obtain a vector which gives me when the derivative is positive or not.

I would like now to obtain the list of the zero-crossing values which are increasing but I have difficulties to obtain it.

By list manipulation, it should be easy to do.

**May you help to plot obtain this list so that I can plot the desired vertical lines?**

Thank you for your help