using FindRoot to find multiple answers in a domain?

*To*: mathgroup at smc.vnet.net*Subject*: [mg69059] using FindRoot to find multiple answers in a domain?*From*: "akil" <akomur at wanadoo.nl>*Date*: Tue, 29 Aug 2006 03:25:42 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

I want to find all answers that exist in a certain domain, but FindRoot gives only the first answer it finds (Using other methods like Solve,Reduce etc takes too long, so Im stuck with using FindRoot). I give the problem I have by example, the functions I use are really complex, but by solving the problem for the example, I could solve t for the complex part. Example: Finding all intersections of Cos[x] and Sin[x] in the domain [0,10Pi] Doing: FindRoot[Cos[antwoord] == Sin[antwoord], {antwoord, 0, 0, 10Pi}] FindRoot[Cos[antwoord] == Sin[antwoord], {antwoord, %, %, 10Pi}] does not work the second FindRoot gives the exact same answer back. So using this in a loop to find all intersections does not work. Doing FindRoot[Cos[antwoord] == Sin[antwoord], {antwoord, %+0.01, %+0.01, 10Pi}] instead, also does not work. Any way to find all intersections in a specified domain? Akil

**Follow-Ups**:**Re: using FindRoot to find multiple answers in a domain?***From:*"Carl K. Woll" <carlw@wolfram.com>