ASKSAGE: Sage Q&A Forum - Individual question feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Mon, 21 Jan 2013 01:51:44 -0600simplify sinh expressionhttps://ask.sagemath.org/question/9723/simplify-sinh-expression/I guess I just ran up against one of those maxima things again, but I thought I would signal the problem anyway.
I would have expected Sage to simplify
sinh(log(1+sqrt(2)))
(it is 1), but Sage doesn't. It doesn't return True to the following either
arcsinh(1)==1+sqrt(2)
or am I missing something?Sun, 20 Jan 2013 04:13:50 -0600https://ask.sagemath.org/question/9723/simplify-sinh-expression/Comment by achrzesz for <p>I guess I just ran up against one of those maxima things again, but I thought I would signal the problem anyway.</p>
<p>I would have expected Sage to simplify</p>
<pre><code>sinh(log(1+sqrt(2)))
</code></pre>
<p>(it is 1), but Sage doesn't. It doesn't return True to the following either</p>
<pre><code>arcsinh(1)==1+sqrt(2)
</code></pre>
<p>or am I missing something?</p>
https://ask.sagemath.org/question/9723/simplify-sinh-expression/?comment=18376#post-id-18376sinh(log(1+sqrt(2))).n()
1.00000000000000
Sun, 20 Jan 2013 04:49:07 -0600https://ask.sagemath.org/question/9723/simplify-sinh-expression/?comment=18376#post-id-18376Answer by DSM for <p>I guess I just ran up against one of those maxima things again, but I thought I would signal the problem anyway.</p>
<p>I would have expected Sage to simplify</p>
<pre><code>sinh(log(1+sqrt(2)))
</code></pre>
<p>(it is 1), but Sage doesn't. It doesn't return True to the following either</p>
<pre><code>arcsinh(1)==1+sqrt(2)
</code></pre>
<p>or am I missing something?</p>
https://ask.sagemath.org/question/9723/simplify-sinh-expression/?answer=14479#post-id-14479Wouldn't be the worst thing in the world if someone had a look at our simplification heuristics. In the meantime:
sage: y = sinh(log(1+sqrt(2)))
sage: y.simplify_full()
sinh(log(sqrt(2) + 1))
sage: y.maxima_methods().exponentialize()
-1/2/(sqrt(2) + 1) + 1/2*sqrt(2) + 1/2
sage: y.maxima_methods().exponentialize().simplify_full()
1
Sun, 20 Jan 2013 06:45:43 -0600https://ask.sagemath.org/question/9723/simplify-sinh-expression/?answer=14479#post-id-14479Comment by kcrisman for <p>Wouldn't be the worst thing in the world if someone had a look at our simplification heuristics. In the meantime:</p>
<pre><code>sage: y = sinh(log(1+sqrt(2)))
sage: y.simplify_full()
sinh(log(sqrt(2) + 1))
sage: y.maxima_methods().exponentialize()
-1/2/(sqrt(2) + 1) + 1/2*sqrt(2) + 1/2
sage: y.maxima_methods().exponentialize().simplify_full()
1
</code></pre>
https://ask.sagemath.org/question/9723/simplify-sinh-expression/?comment=18368#post-id-18368Really, we have to decide if we want complete granularity like Maxima, which leads to things without ambiguity because you would choose whether to use methods that "simplify" multivalued functions like log, or to continue our current point of adding more and more methods to simplification. I lean toward the latter, but maybe it's time to think about that again.Mon, 21 Jan 2013 01:51:44 -0600https://ask.sagemath.org/question/9723/simplify-sinh-expression/?comment=18368#post-id-18368