Đáp án:
Giải thích các bước giải:
\(\begin{array}{l}
b.{x^4} - 4x + 1 = 0\\
\to \left[ \begin{array}{l}
x = 1.493358557\\
x = 0.2509921575
\end{array} \right.
\end{array}\)
BXD:
x -∞ 0.2509921575 1.493358557 +∞
f(x) + 0 - 0 +
\(\begin{array}{l}
d.{x^3} - 3x + 2 = 0\\
\to \left( {x - 1} \right)\left( {{x^2} + x - 2} \right) = 0\\
\to {\left( {x - 1} \right)^2}\left( {x + 2} \right) = 0\\
\to \left[ \begin{array}{l}
x = 1\\
x = - 2
\end{array} \right.
\end{array}\)
BXD:
x -∞ -2 1(kép) +∞
f(x) - 0 + 0 +
