Question

[Tien Do]

Giúp mk mấy câu này với

Answer 1

[Hoàng Tử Hà]

Lần sau bạn đăng riêng ra nhé

1/

a/  \(\lim\limits_{x\rightarrow2}\dfrac{2^2-4.2-2}{\sqrt{2+7}-5}=3\) 

b/ \(\lim\limits_{x\rightarrow2}\dfrac{2\left(x-2\right)\left(x-\dfrac{1}{2}\right)\left(\sqrt{3x-2}+2\right)}{3\left(x-2\right)}=\dfrac{2\left(2-\dfrac{1}{2}\right)\left(\sqrt{3.2-2}+2\right)}{3}=...\)

c/ \(\lim\limits_{x\rightarrow-\infty}\dfrac{-\dfrac{3x}{x}+\dfrac{1}{x}}{-\sqrt{\dfrac{4x^2}{x^2}-\dfrac{3x}{x^2}+\dfrac{1}{x^2}}+\dfrac{x}{x}}=\dfrac{-3}{-2+1}=3\)

2/ 

\(\lim\limits_{x\rightarrow-1^+}f\left(x\right)=\lim\limits_{x\rightarrow-1^+}\dfrac{2x^2+5x+3}{x+1}=\lim\limits_{x\rightarrow-1^+}\dfrac{2\left(x+1\right)\left(x+\dfrac{3}{2}\right)}{x+1}=1=\lim\limits_{x\rightarrow-1^-}f\left(x\right)\)

\(f\left(x\right)=3.2021+4=...\)

\(\lim\limits_{x\rightarrow1}f\left(x\right)\ne f\left(x\right)\) => ham so gian doan tai x=-1

b/ \(f\left(x\right)=\lim\limits_{x\rightarrow-1}f\left(x\right)\Leftrightarrow3m+4=1\Leftrightarrow m=-1\)

3/ Kia là -ax-b hay cộng nhỉ?