ArcTan[x, 0] With Numeric Values

*To*: mathgroup at smc.vnet.net*Subject*: [mg30544] ArcTan[x, 0] With Numeric Values*From*: "David Park" <djmp at earthlink.net>*Date*: Tue, 28 Aug 2001 04:54:49 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Dear MathGroup, Why does this two argument form of ArcTan not automatically simplify with numeric input? It does simplify with number input. {ArcTan[5, 0], ArcTan[Sqrt[5], 0], ArcTan[Pi, 0]} Simplify[%] FullSimplify[%] {0, ArcTan[Sqrt[5], 0], ArcTan[Pi, 0]} {0, 0, ArcTan[Pi, 0]} {0, 0, 0} One would normally expect the same simplification to automatically occur in all three of these cases. David Park djmp at earthlink.net http://home.earthlink.net/~djmp/