Re: Limit[ArcTan]
- To: mathgroup at smc.vnet.net
- Subject: [mg20783] Re: Limit[ArcTan]
- From: "Bill Bertram" <wkb at ansto.gov.au>
- Date: Thu, 11 Nov 1999 00:22:53 -0500
- Organization: Australian Nuclear Science and Technology Organisation
- References: <80auib$j32@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Alberto Verga wrote in message <80auib$j32 at smc.vnet.net>... >Why I do not obtain the correct result? > ArcTan[x,x^2]/.x->-0.00001 >gives > 3.14158 >But, > Limit[ArcTan[x,x^2],x->0,Direction->-1] >gives > 0 Alberto, You probably misuderstand what is meant by Direction->-1. It means approaching the limit from the large values to the small value. Thus in your example Limit[ArcTan[x,x^2],x->0,Direction->-1] takes the limit from positive x to zero. To get the limit you want you need to use Direction -> +1. Cheers Bill