> > Hi, I'm wondering if it is possible to insert a number into symbolic > > equation. For example: > > > sage: y = x^2 > > sage: diff(y) > > 2*x > > > now is it possible to take the results of the derivative, define x as > > say 3, and get a numeric answer? Thanks > > Try this: > sage: g = diff(y) > sage: g > x |--> 2*x > sage: g(3) > 6
That usage is deprecated. "g" in this case would evaluate to the expression "2*x", not the function "x |--> 2*x". You can plug in a value for x using the "subs" method: sage: y = x^2 sage: diff(y) 2*x sage: diff(y).subs(x=3) 6 sage: diff(y).subs(x=pi) 2*pi Alternatively, if you define "y" as a function, "g" would be a function: sage: y(x) = x^2 sage: y x |--> x^2 sage: g = diff(y) sage: g x |--> 2*x sage: g(3) 6 sage: g(pi) 2*pi Hope this helps. -- Tianwei -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
