I want to calculate non numeric roots of a polynomial in the form a+sqr(b)/c. For example numeric roots of the polynomial f(x)=x4-270x2-140x+1200 are

Root 1: -16.018

Root 2: -2.413

Root 3: 1.876

Root 4: 16.555

But i want to calculate in the form a+sqr(b)/c. Actually i am interested in discriminant b. is there any program which calculate roots in a+sqr(b)/c form.