<![CDATA[Syntax for multivariable functions]]>
https://help.geogebra.org/topic/syntax-for-multivariable-functions
Sat, 14 Jul 2018 10:45:25 +0000Fri, 13 Jul 2018 23:13:30 +0000Zend_Feed<![CDATA[Hi tpgettys! I understand your point and now the famous .... but ;-) There is a difference between e. g. f(x)=x² and y=x². The second one is a conic and you have to use this form to have the conic-commands available. I realize the difference here in Simonas reply: https://help.geogebra.org/topic/tangente-wird-nicht-richtig-gelegt and the difference is a little bit hidden in this section: https://wiki.geogebra.org/e... You may enter a conic section as a quadratic equation in x and y. And I think that's why e. g. f(y)=2*y is forbidden, but x=2*y and f(s)=2*s are allowed (the lines are different). Hope that helps you and kind regards mire2]]>
https://help.geogebra.org/topic/syntax-for-multivariable-functions#comment-242842
Sat, 14 Jul 2018 10:45:25 +0000<![CDATA[another solution: Reflect(x² + y², y = z)]]>
https://help.geogebra.org/topic/syntax-for-multivariable-functions#comment-242824
Sat, 14 Jul 2018 05:55:33 +0000<![CDATA[Hi mire2, and thanks for your reply. I understand that x, y and z are not allowed in the Surface() command, which seems to suggest that those letters are dedicated to specific usage. In the 2D window if you enter f(y)=2*y you will get an error; x just be used for the independent variable. This difference should be documented somewhere, as it a source of great confusion (at least in my mind!), but I have not run across it yet.]]>
https://help.geogebra.org/topic/syntax-for-multivariable-functions#comment-242818
Sat, 14 Jul 2018 03:17:09 +0000<![CDATA[]]>
https://help.geogebra.org/topic/syntax-for-multivariable-functions#comment-242820
Sat, 14 Jul 2018 05:08:58 +0000<![CDATA[Hi tpgettys! I think that the name of the two variables are always interpreted as x- and y-value. If you type f(a,b)=a²+b² you will get the same picture, because the first variable a is dedicated to x and the second b is dedicated to y and so the function-value is always dedicated to z. So if you want to have a paraboloid around the y-axis you can use the surface-command Surface(u, u² + v², v, u, -10, 10, v, -10, 10)note that x, y, z are not allowed as variables, but I think, they rename it internal if you use them: https://wiki.geogebra.org/e... or an equation like y-x²-z²=0 Kind regards mire2]]>
https://help.geogebra.org/topic/syntax-for-multivariable-functions#comment-242812
Sat, 14 Jul 2018 00:02:27 +0000