ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Fri, 07 Aug 2020 13:21:22 +0200What does r in an answer meanhttps://ask.sagemath.org/question/52904/what-does-r-in-an-answer-mean/After I ran the following I got a valid image but what do the `r`'s
stand for in the solve part? They don't seem to have a value
but I didn't get an error.
var('x y')
show(plot3d(x^2 + y^2, (x,-2,2), (y,-2,2)))
[image]
solve(x^2 + y^2==0,[x,y])
[[x == r1, y == I*r1], [x == r2, y == -I*r2]]Fri, 07 Aug 2020 12:19:19 +0200https://ask.sagemath.org/question/52904/what-does-r-in-an-answer-mean/Comment by cybervigilante for <p>After I ran the following I got a valid image but what do the <code>r</code>'s
stand for in the solve part? They don't seem to have a value
but I didn't get an error.</p>
<pre><code>var('x y')
show(plot3d(x^2 + y^2, (x,-2,2), (y,-2,2)))
</code></pre>
<p>[image]</p>
<pre><code>solve(x^2 + y^2==0,[x,y])
[[x == r1, y == I*r1], [x == r2, y == -I*r2]]
</code></pre>
https://ask.sagemath.org/question/52904/what-does-r-in-an-answer-mean/?comment=52906#post-id-52906For some reason the y answer is sqrt(-1) times r1, etc, but isn't showing up in my query.Fri, 07 Aug 2020 12:23:59 +0200https://ask.sagemath.org/question/52904/what-does-r-in-an-answer-mean/?comment=52906#post-id-52906Answer by slelievre for <p>After I ran the following I got a valid image but what do the <code>r</code>'s
stand for in the solve part? They don't seem to have a value
but I didn't get an error.</p>
<pre><code>var('x y')
show(plot3d(x^2 + y^2, (x,-2,2), (y,-2,2)))
</code></pre>
<p>[image]</p>
<pre><code>solve(x^2 + y^2==0,[x,y])
[[x == r1, y == I*r1], [x == r2, y == -I*r2]]
</code></pre>
https://ask.sagemath.org/question/52904/what-does-r-in-an-answer-mean/?answer=52907#post-id-52907Sometimes solving an equation gives a family of solutions with
one or more parameters.
Complex-valued parameters are denoted by `c1`, `c2`, etc.
Real-valued parameters are denoted by `r1`, `r2`, etc.
Integer-valued parameters are denoted by `z1`, `z2`, etc.
Example:
sage: solve (x - x == 0, x)
[x == r1]Fri, 07 Aug 2020 12:31:04 +0200https://ask.sagemath.org/question/52904/what-does-r-in-an-answer-mean/?answer=52907#post-id-52907Comment by slelievre for <p>Sometimes solving an equation gives a family of solutions with
one or more parameters.</p>
<p>Complex-valued parameters are denoted by <code>c1</code>, <code>c2</code>, etc.</p>
<p>Real-valued parameters are denoted by <code>r1</code>, <code>r2</code>, etc.</p>
<p>Integer-valued parameters are denoted by <code>z1</code>, <code>z2</code>, etc.</p>
<p>Example:</p>
<pre><code>sage: solve (x - x == 0, x)
[x == r1]
</code></pre>
https://ask.sagemath.org/question/52904/what-does-r-in-an-answer-mean/?comment=52908#post-id-52908See related questions and answers:
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- [Ask Sage question 7927: Solve() confusion...](https://ask.sagemath.org/question/7927)Fri, 07 Aug 2020 13:21:22 +0200https://ask.sagemath.org/question/52904/what-does-r-in-an-answer-mean/?comment=52908#post-id-52908