Two FindRoot questions
- To: mathgroup at smc.vnet.net
- Subject: [mg89872] Two FindRoot questions
- From: Aaron Fude <aaronfude at gmail.com>
- Date: Mon, 23 Jun 2008 02:48:44 -0400 (EDT)
Hi,
These are not FindRoot questions, per se...
Here's a simple example which I want to ask three questions about:
f[k_] := x /. FindRoot[x^2 + k, {x, 0, 10}];
f[-10]
Plot[f[k], {k, -10, 10}]
First, I want the plot to only show where there exists a root.
Is the right solution to make f[] return Null?
How do I make f[] return Null? (Is there a way to "catch" the
warnings?)
Finally, I need to solve my equations to 20 digits. How do I do that?
I've read about Accuracy and Precision but it didn't help.
Thanks!