f(x) = x^6+x^5-7*x^4

[Maple Plot]

matrix([[`x points above:`, -3.193, -2.617, -2.040, 0., 1.373, 1.783, 2.193], [`a zero of f ?`, __, __, __, __, __, __, __], [`x-inter of f ?`, __, __, __, __, __, __, __], [`a zero of f ' ?`, __, __, ...