Question

Найдите нули функции; y=x^4-6x^2-7

Answer 1

$y=0: x^4 - 6x^2 - 7 = 0 x^2 = t, t\ \textgreater \ 0 t^2 - 6t - 7 = 0 t_1+t_2 = -p t_1 * t_2 = q t_1 = -1, t\ \textgreater \ 0 ne podhodit t_2 = 7 x^2 = 7 x = -\sqrt7 x=\sqrt7$