Tagged Questions
9
votes
1answer
151 views
Why is ReplaceAll behaving like this?
I'm learning to use the ReplaceAll function and I found the behavior of which is quite confusing.
For
Sqrt[f[x, y]] /. f[___] -> u
Mathematica returns
...
16
votes
5answers
484 views
How do I get my equation to have the form $(x-a)^2 + (y-b)^2 + (z-c)^2-d = 0$?
I want Mathematica to express the equation $$-11 - 2 x + x^2 - 4 y + y^2 - 6 z + z^2=0$$ in the form $$(x - 1)^2 + (y - 2)^2 + (z - 3)^2 - 25=0$$ How do I tell Mathematica to do that?
7
votes
1answer
254 views
How do I expand a sum?
I have a problem with Mathematica's symbolic manipulations. As an example, consider the following expression:
$$\sum _{i=1}^n -2 x_i \left(-a x_i-b+y_i\right)=0$$
How do I get Mathematica to expand ...
