Re: Division by zero, despite strong hint

*To*: mathgroup at smc.vnet.net*Subject*: [mg96576] Re: [mg96542] Division by zero, despite strong hint*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Mon, 16 Feb 2009 16:38:58 -0500 (EST)*Reply-to*: hanlonr at cox.net

You left a comma out g3[x_] := Piecewise[{{Sin[1/x], x != 0}, {0, x == 0}}] Plot[g3[x], {x, 0, 1}, PlotStyle -> Red] However, the second condition is unnecessary since the default is zero g3[x_] := Piecewise[{{Sin[1/x], x != 0}}] Plot[g3[x], {x, 0, 1}, PlotStyle -> Red] Bob Hanlon ---- dch888 <dch888 at googlemail.com> wrote: ============= Hi, I'm trying to plot the Sin[1/x] curve with the curve being defined as 0 at 0 like this: g3[x_] := Piecewise[{{Sin[1/x], x != 0} {0, x == 0}}] Invoking Plot produced a flat graph; puzzled I asked for g3[0] and got: Power::infy Infinite expression 1/0 encountered >> { {Indeterminate, False True}, {0, \!\(\* TagBox["True", "PiecewiseDefault", AutoDelete->False, DeletionWarning->True]\)} } Hmmm... what's the trick here to stop Mathematica evaluating all the branches of the piecewise fn? There's nothing in the documentation that I can see to stop this in Piecewise... perhaps I need to use a different Mathematica function? Thanks, David.