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.Mon, 04 Aug 2014 09:32:54 +0200Solve equations with sin(x)https://ask.sagemath.org/question/23652/solve-equations-with-sinx/ Hi. I want to know why sage can't solve the euqations: [4*sin(x)+y==5,sin(x)==y] (It's so easy!)and it just gives back: [sin(x)==y,y+4*sin(x)==5]. Can you help me?Fri, 01 Aug 2014 03:50:32 +0200https://ask.sagemath.org/question/23652/solve-equations-with-sinx/Comment by rws for <p>Hi. I want to know why sage can't solve the euqations: [4<em>sin(x)+y==5,sin(x)==y] (It's so easy!)and it just gives back: [sin(x)==y,y+4</em>sin(x)==5]. Can you help me?</p>
https://ask.sagemath.org/question/23652/solve-equations-with-sinx/?comment=23656#post-id-23656What command did you give?Fri, 01 Aug 2014 18:51:38 +0200https://ask.sagemath.org/question/23652/solve-equations-with-sinx/?comment=23656#post-id-23656Answer by dazedANDconfused for <p>Hi. I want to know why sage can't solve the euqations: [4<em>sin(x)+y==5,sin(x)==y] (It's so easy!)and it just gives back: [sin(x)==y,y+4</em>sin(x)==5]. Can you help me?</p>
https://ask.sagemath.org/question/23652/solve-equations-with-sinx/?answer=23670#post-id-23670Solving equations is done through the solve command, which is documented [here](http://www.sagemath.org/doc/tutorial/tour_algebra.html). I went to a Sage cell server and typed in:
solve(5-4*sin(x)==sin(x),x)
and got an answer: [x == 1/2*pi]. Of course, since the trig functions are periodic there are an infinite number of solutions.
Since you haven't given the code that resulted in the output you describe, it's impossible for me to know what went wrong. Always provide your code; it makes it easier to diagnose what is wrong.
Sat, 02 Aug 2014 18:05:49 +0200https://ask.sagemath.org/question/23652/solve-equations-with-sinx/?answer=23670#post-id-23670Comment by god.one for <p>Solving equations is done through the solve command, which is documented <a href="http://www.sagemath.org/doc/tutorial/tour_algebra.html">here</a>. I went to a Sage cell server and typed in:</p>
<pre><code>solve(5-4*sin(x)==sin(x),x)
</code></pre>
<p>and got an answer: [x == 1/2*pi]. Of course, since the trig functions are periodic there are an infinite number of solutions. </p>
<p>Since you haven't given the code that resulted in the output you describe, it's impossible for me to know what went wrong. Always provide your code; it makes it easier to diagnose what is wrong.</p>
https://ask.sagemath.org/question/23652/solve-equations-with-sinx/?comment=23680#post-id-23680On sagenb.org using
var('x,y');
solve([y==sin(x),y+4*sin(x)==5],x,y)
I get
[y == sin(x), y + 4*sin(x) == 5]
as a solutionSun, 03 Aug 2014 13:32:21 +0200https://ask.sagemath.org/question/23652/solve-equations-with-sinx/?comment=23680#post-id-23680Answer by rws for <p>Hi. I want to know why sage can't solve the euqations: [4<em>sin(x)+y==5,sin(x)==y] (It's so easy!)and it just gives back: [sin(x)==y,y+4</em>sin(x)==5]. Can you help me?</p>
https://ask.sagemath.org/question/23652/solve-equations-with-sinx/?answer=23686#post-id-23686Congratulations, you have found a bug! I have reported it at
http://trac.sagemath.org/ticket/16753 Mon, 04 Aug 2014 09:32:54 +0200https://ask.sagemath.org/question/23652/solve-equations-with-sinx/?answer=23686#post-id-23686