Content deleted Content added
m Signing comment by 98.232.93.206 - "→Decidability unknown for elementary functions: " |
|||
Line 162:
But isn’t <math>|x|=\sqrt{x^2}</math> elementary presentable? --[[User:Chricho|Chricho ∀]] ([[User talk:Chricho|talk]]) 23:07, 26 June 2012 (UTC)
:The problem is that there are 2 square roots to each number, and the choice between them cannot be controlled. So <math>\sqrt{x^2}</math> could also mean <math>x</math>, or <math>-x</math>--[[Special:Contributions/77.126.235.228|77.126.235.228]] ([[User talk:77.126.235.228|talk]]) 14:34, 13 May 2013 (UTC)
::I agree with Chriko. Nowadays the <math>\sqrt{}</math> symbol is most widely used to mean "the positive square root of". An example of this is the quadratic formula. If the symbol were used to signify both the positive and negative square root we wouldn't need the plus or minus sign before it. Also <math>\sqrt{x}</math> would not be a function if that symbol were used for both the positive and negative square root. <span style="font-size: smaller;" class="autosigned">— Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/98.232.93.206|98.232.93.206]] ([[User talk:98.232.93.206|talk]]) 05:22, 20 October 2013 (UTC)</span><!-- Template:Unsigned IP --> <!--Autosigned by SineBot-->
== A New Algorithm ==
| |||