119. If $f(x) = x^3 - x^2 + 2x$, the equation of the line perpendicular to the curve of $f^{-1}$ at the point $x = 2$ is which of the following? (1) $y + 3x = 7$ (2) $y - 3x = -5$ [6pt] (3) $3y + x = 5$ (4) $3y - x = 1$ 120. For the graph of $y = |x| \cdot e^{-x}$, on which interval is it decreasing and concave down? (1) $(-\infty, 2)$ (2) $(0, 1)$ [6pt] (3) $(1, 2)$ (4) $(2, +\infty)$
\textbf{119.} If $f(x) = x^3 - x^2 + 2x$, the equation of the line perpendicular to the curve of $f^{-1}$ at the point $x = 2$ is which of the following?
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(1) $y + 3x = 7$ \hspace{4cm} (2) $y - 3x = -5$\\[6pt]
(3) $3y + x = 5$ \hspace{4cm} (4) $3y - x = 1$
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\textbf{120.} For the graph of $y = |x| \cdot e^{-x}$, on which interval is it decreasing and concave down?
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(1) $(-\infty, 2)$ \hspace{3cm} (2) $(0, 1)$\\[6pt]
(3) $(1, 2)$ \hspace{3cm} (4) $(2, +\infty)$
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