Re: How can I find roots in Mathematica 6?
- To: mathgroup at smc.vnet.net
- Subject: [mg83558] Re: How can I find roots in Mathematica 6?
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Thu, 22 Nov 2007 06:40:12 -0500 (EST)
- Organization: The Open University, Milton Keynes, UK
- References: <email@example.com>
DrunkenButterfly wrote: > Does anyone know what should I type in in order to find the roots of > > cosh(z)=i with Abs[Im[z]]<10 ? > > I've just started using Mathematica 6 and the help browser is not really helping me at all. Thanks! Every built-in function name starts will an Uppercase letter (even if the name is only one letter long) and square braces are used to pass arguments (a function f(...) is written f[...], of course with some meaningful arguments between the square braces). So cosh(z) is Cosh[z] and the imaginary unit Sqrt[-1] is I (uppercase i). Test for equality is denoted by == (a double equal sign, a single one is for assigning a value to a symbol). Finally, the solver Reduce accepts a mix of equalities and inequalities and works by default on the complex field. Having said that, In:= Reduce[Cosh[z] == I && Abs[Im[z]] < 10, z] Out= z == -2*I*Pi - ArcCosh[I] || z == 2*I*Pi - ArcCosh[I] || z == -ArcCosh[I] || z == ArcCosh[I] || z == -2*I*Pi + ArcCosh[I] || z == 2*I*Pi + ArcCosh[I] Regards, -- Jean-Marc