Using maxima for high school mathematics



On Sun, Apr 03, 2011 at 06:08:15PM +1000, David Billinghurst wrote:
> On 3/04/2011 3:51 PM, Daniel Dalton wrote:
> >4) Finally, I'm having trouble solving some more complicated equations
> >with maxima. According to my text book there is real solutions. How can
> >I find the real solution for the below equation? Input/output is
> >below. (Note, I'm not familiar with complex numbers.)
> Hi Dan,

Hi David,

> 
> There are at least two ways to attack 4)
> 
> 1. Float isn't always sufficient with complex numbers.  Try
> rectform(float(expression))).  You are left with a small imaginary
> part due to rounding errors.
> 
> 2. Use the realroots() function to extract the real roots.  It
> returns rational approximations to the real solution, which can be
> converted to floating point using float().  Try realroots(x^2-2=0).

This does the job perfectly! Thank you. 

> Do you understand that maxima approximating the irrational number
> sqrt(2)?

Yes.

Thanks for your help,

Dan