Limit involving square root
- To: mathgroup at smc.vnet.net
- Subject: [mg30167] Limit involving square root
- From: Hugh Goyder <goyder at rmcs.cranfield.ac.uk>
- Date: Wed, 1 Aug 2001 02:19:22 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Dear Mathgroup, Below I take the limit of a function and then the limit of 1 plus the same function. A plot of the function shows that the first result, (5), is correct but the second, (1), is wrong. (Should be 6.) What's happening? In[1]:= $Version Out[1]= 4.1 for Microsoft Windows (November 2, 2000) In[2]:= Limit[x - Sqrt[9 - 10 x + x^2],x -> Infinity] Out[2]= 5 In[3]:= Limit[1 + x - Sqrt[9 - 10 x + x^2],x -> Infinity] Out[3]= 1 I also note that using Series to expand about infinity does give the correct answers. Thanks Hugh Goyder