roots of cubic equation

[jmat]

hello, excuse my English ....
I've been trying to solve a cubic equation of the form -x^3 -6*k*x^2 +6*k*x +7k^3 obtaining the roots of x as a function of k = constant ;roots should be x = 4.14; x = 2.52; x = -0.66 but did not obtain the Nspire

thank you

[critor]

So you are suggesting that the roots are keeping the same values for every value of k.

Indeed, the TI-Nspire doesn't manage to simplify the roots expressions by removing the k occurrences.

But it seems totally normal, as if we assign different values to k, we clearly see that the roots values do change.


So, something's wrong in your first post.

[Bisam]

S'il y a un k^2*x à la place du k*x, alors toutes les solutions seront proportionnelles à k... avec le même coeff.
Mais là, ce n'est pas le cas.

[jmat]

thank you