Equation solver returning too few solutions to trig equation

[jrkimber]

Hi,

When solving the following equation in the range 0 - 360 degrees, 360 degrees should be a solution. The calculator omits it, however.

Increasing the upper end of the range to 360.00001 returns the solution of 360 degrees.

Thanks,
James

[fbeleznay]

If you are looking into this issue (and it is also related to another post about asking for exact solution of trigonometric equations), please have also a look at the following equation:


Numworks gives eight solutions:

However, at four of these the left hand side of the equation is not defined, so actually there are only four solutions.

This is also related to my other post (right below this one, about solutions not being in the domain of the equation), but since that one has no reaction, I thought I also mention it here, too. I know that this can be tricky to deal with numerically (since without CAS one cannot really find exact solutions), but nevertheless this is a problem, which I think at least could be mentioned in the manual.

[jrkimber]

Hi,

I've just noticed that this is also a problem when solving simple equations in radians.

For the following equation, 2pi should be a solution but is not. This is quite misleading for students.

Thanks,
James

[adri1numworks]

Hi,
Thank you for your input. These are two different issues.
Concerning the interval of search @jrkimber , the fact that the last value is excluded from the interval of research is a problem we identified. We will let you know when we correct it !

For the topic mentioned by @fbeleznay : this is indeed linked to the fact that we solve equations numerically. I will answer on the other topic you raised : #2152

Thanks