Re: Asymptote strangeness...
- To: mathgroup at smc.vnet.net
- Subject: [mg38874] Re: Asymptote strangeness...
- From: mathma18 at hotmail.com (Narasimham G.L.)
- Date: Thu, 16 Jan 2003 03:22:02 -0500 (EST)
- References: <b033br$n11$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Mike Summers wrote :
f[x] = (x + 2)/(Abs[x] - 2) should have asymptotes at 2 & -2.
Plot[Evaluate[f[x]], {x, -5, 5}] only shows the asymptote at 2.
The function above has vanishing denominator or x pole at positive x=2 only.
However,note that x and Abs[x] are DIFFERENT algebraic variables .If
you want to include double signed nature of x {ignored in Abs[x]},then write:
g[x] = (Abs[x] + 2)/(Abs[x] - 2) Or, the same as
h[x]=(Abs[x] + 2)^2/(x^2-4)
Plot[Evaluate[f[x]], {x, -5, 5}]
Plot[Evaluate[g[x]], {x, -5, 5}]
Plot[Evaluate[h[x]], {x, -5, 5}] which is an even function in x, plot
is symmetric on y-axis.
HTH