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Solving within bounds (SOLVED), and a suggestion.
03-09-2015, 01:25 AM (This post was last modified: 03-09-2015 02:39 AM by pwarmuth.)
Post: #1
Solving within bounds (SOLVED), and a suggestion.
I cannot seem to locate the bounding operator on the HP Prime. It's not even in the catalog, and the help contents for the solve() and zeros() functions do not show how one can go about doing this. So I am left to question whether this calculator supports this functionality. Am I able to do something like the following on HP Prime?

solve(sin(x)=0,x|0<x<2pi) in radian mode or zeros(sin(x)|0<x<720) in degree mode.

Funny thing, I found it the solution(s) shortly after I submitted this. You can use one of two things to get this behavior. There is indeed a pipe operator, and it's third from the left on the top row of the templates dialog. It is also in the character dialog. Secondly, you can place bounds on a variable prior to calculation by using the assume() command.

assume(x>0 AND x<4*pi)

Then run your solve and it will spit out the answers you are looking for. Be sure to purge() that variable afterwards (or delete it from the variables menu).
now back to the original post
It would also be nice if in the home screen it I could choose whether or not it will display exact values. If I input sqrt(2) + 1, it displays the answer as a numerical approximation. I'd like to be able to get exact value as an answer if I need it. This would be particularly useful for the trigonometric ratios. cos(45) = sqrt(2)/2. I want to have the option for it to show me the radical, rather than only giving a numerical approximation. Sometimes the use of the CAS is restricted, and it removes a lot of the niceties when you're forced into using only numerical approximations to verify your answers.
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09-09-2015, 05:57 PM
Post: #2
RE: Solving within bounds (SOLVED), and a suggestion.
Please note that you can add to the constraints on a variable by using additionally after an assume. A second assume simply overwrites the first. As for the exact arithmetic comment, Home is specifically for numerical approximations and CAS is specifically for exact arithmetic. It sounds like you want to mix the two and we will simply not be able to support this any time soon. On the other hand, if you use CAS, they can uncheck the Exact CAS setting and the CAS will return numerical approximations. This may get you close to the desired behavior.

Hope this helps.
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