Tìm giới hạn lim x→(−1)+ 2x−1/ 2+2x

Question

Tìm giới hạn \({\mathop{\lim }\limits_{x\to \left(-1\right)^{+} }} \frac{2x-1}{2+2x}\) .

\(A.-\infty . \)

\(B. +\infty . \)

\(C. \frac{2}{3} . \)

\(D. -\frac{2}{3} .\)

Answer 1

Chọn A

Ta có \({\mathop{\lim }\limits_{x\to \left(-1\right)^{+} }} \frac{2x-1}{2+2x} =-\infty  \)

\(vì \left\{\begin{array}{l} {{\mathop{\lim }\limits_{x\to \left(-1\right)^{+} }} \left(2x-1\right)=-3<0} \\ {{\mathop{\lim }\limits_{x\to \left(-1\right)^{+} }} \left(2x+2\right)=0} \\ {2x+2>0\, \, \, khi\, \, x>-1} \end{array}\right. .\)