Can I force the symbolic result to return only real values
In general, I think no.
Is 'float' required to evaluate the symbolic expression numerically
You can put a floating point number somewhere in your expression, then you will get a floating point answer (for example, put k.6*1.0). If you do use float then 8 digits is not enough though. Remember that float does not just affect the displayed answer, it affects the precision of the calculations. Check how much error you have in your equality with float 8: about 6,000,000. With float 20 the error is 0.03.
Is there a more elegant way to solve this equation.
I would automate the picking of the real root.
