Cho lim x suy ra 3 f(x) = 4, chứng minh rằng lim x suy ra 3 căn bậc hai f(x) = 2
Cho\(\mathop {\lim }\limits_{x \to 3} f\left( x \right) = 4\), chứng minh rằng:
\(\mathop {\lim }\limits_{x \to 3} \sqrt {f\left( x \right)} = 2\).
\(\mathop {\lim }\limits_{x \to 3} \sqrt {f\left( x \right)} = \sqrt {\mathop {\lim }\limits_{x \to 3} f\left( x \right)} = \sqrt 4 = 2\).