Cho hàm số f ( x ) = x − x^2 / | x | . Khi đó lim x → 0 − f ( x ) bằng

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Cho hàm số \(f\left( x \right) = \frac{{x - {x^2}}}{{\left| x \right|}}\). Khi đó \(\mathop {\lim }\limits_{x \to {0^ - }} f\left( x \right)\) bằng

\( - \infty \).

\(1\).

\(0\).

\( - 1\).

Giải thích

\(\mathop {\lim }\limits_{x \to {0^ - }} f\left( x \right) = \mathop {\lim }\limits_{x \to {0^ - }} \frac{{x - {x^2}}}{{\left| x \right|}}\)\[ = \mathop {\lim }\limits_{x \to {0^ - }} \frac{{x\left( {1 - x} \right)}}{{ - x}}\]\[ = \mathop {\lim }\limits_{x \to {0^ - }} \left( {x - 1} \right) = - 1\]. Chọn D.