I have tested my lagrange constrained method
with this example:
f:x^(4/5)*y^(1/5)
g:x+y-1
lagrange(f,g)
[(4*4^(4/5))/5-16/(5*4^(1/5)),-4.4408920985006262*10^-16]
Minimo vincolato in[x=4/5,y=1/5,k=-(2*2^(3/5))/5]f(z)=4^(4/5)/5
Maxima 5.18 works correctly
and founds x=4/5 y=1/5
Maxima 5.19
founds de=0 indecision case.
[0,0.0]
Nessuna conclusione