disi's profile - activity

again, this works perfect :)

for a in maxSol:
    if a[x] in RR:
        print RealField(50)(a[x])

for self reference, this is what I got:

I think "a in RR" is what you want to use. Your first attempt could work too, using a try/except block.

For testing integrality, or rationality, "in ZZ" and "in QQ" work similarly.

And if you know the numbers you're checking are complex, you could also test to see whether their imaginary parts are zero.

Thanks so much :)

I get several results and want to check, which one is a real number. From trial and error, I can see that maxSol[2][x] is the only plausable solution.

Is there something like isReal()?

my attempt (don't laugh) ;)

for i in maxSol: print RealField(50)(i)

where I obviously get: TypeError: Unable to convert x (='.....

that works perfect, thanks :)

sage: A(x)=x/2+(4-x*x)^(1/2)

sage: solve(diff(A(x),x),x,to_poly_solve=true)

[x == 2/5*sqrt(5)]

Here is what I am trying to do:

var('x')
A(x)=x/2+(4-x*x)^(1/2)
assume(0<x<2)
maximum = (derivative(A)==0).maxima_methods().rootscontract().simplify()
view(maximum)
view(solve(maximum,x))
A.plot(A,0,2)

and get i multiplied by the root of x^2... if I put the same equation into wolfram, it gives me a real number 2/sqrt(5) (which is correct and makes sense).

How can I make SageMath solve those? I tried simplify() and full_simplify(), maxima_methods() and rootscontract() gives an error in combination with solve().

I guess it's just some syntax error, sorry for that :(

For now I do most in the Sage - Cell Server, which is great.