frederico firmo's profile - activity

Thanks a lot. My sage version is 8.0 . But it is quiet strange because I tried once more, using the same lines but now it works. The other roots that "did not appear" in the first time came desguised as complex but are indeed real, as the plot of the function shows, and also a simple command float gives. I really don''t know why

The equation below

 f=-32/59049*r^6 + 32/2187*r^5 - 32/243*r^4 + 352/729*r^3 - 56/81*r^2 +
8/27*r

solve(f,r)

[r=−3*sqrt(3)/2+9,r=3*sqrt(3)/2+9,r=0]