Chọn C
lim x → 3 3 x 2 − 4 x − 6 = 3.3 2 − 4 3 − 6 = − 23 3
Chọn C
lim x → 3 3 x 2 − 4 x − 6 = 3.3 2 − 4 3 − 6 = − 23 3
c) lim\(\dfrac{\sqrt{x+3}-3}{x-6}\)(x-->6)
d) lim\(\dfrac{2x-6}{4-x}\)(x-->+\(\infty\))
Tìm các giới hạn sau:
\(\lim\limits_{x\rightarrow-\infty}\) \(\dfrac{\sqrt{x^6+2}}{3\text{x}^3-1}\)
\(\lim\limits_{x\rightarrow+\infty}\) \(\dfrac{\sqrt{x^6+2}}{3\text{x}^3-1}\)
\(\lim\limits_{x\rightarrow-\infty}\) \(\left(\sqrt{2\text{x}^2+1}+x\right)\)
\(\lim\limits_{x\rightarrow1}\) \(\dfrac{2\text{x}^3-5\text{x}-4}{\left(x+1\right)^2}\)
tính giới hạn
a) \(\lim\limits_{x\rightarrow-2}\dfrac{4-x^2}{2x^2+7x+6}\)
b) \(\lim\limits_{x\rightarrow4}\dfrac{2x^2-13x+20}{x^3+64}\)
c) \(\lim\limits_{x\rightarrow-1}\dfrac{2x^2+8x+6}{-2x^2+7x+9}\)
\(a,\lim\limits_{x\rightarrow2}\dfrac{x^3+2x^2-6x-4}{8-x^3}\)
\(b,\lim\limits_{x\rightarrow2}\dfrac{x^3+x^2-5x-2}{x^2-3x+2}\)
Tìm các số thực a, b thỏa mãn \(\lim\limits_{x\rightarrow1}\)\(\dfrac{2x^2+ax+b}{x^2+2x-3}=\dfrac{3}{4}\)
a) lim\(\dfrac{x^2-1}{x+1}\)(x-->-3)
b) lim\(\dfrac{4-x^2}{x+2}\)(x-->-2)
tính giới hạn
a) \(\lim\limits_{x\rightarrow4}\dfrac{\sqrt{2x+8}-4}{x-4}\)
b) \(\lim\limits_{x\rightarrow2}\dfrac{x^2-4}{\sqrt{4x+1}-3}\)
c) \(\lim\limits_{x\rightarrow2}\dfrac{x-2}{2-\sqrt{x+2}}\)
tính giới hạn
a) \(\lim\limits_{x\rightarrow3}\dfrac{x^2-9}{x^2-5x+6}\)
b) \(\lim\limits_{x\rightarrow5}\dfrac{x^2-5x}{x-5}\)
c) \(\lim\limits_{x\rightarrow-3}\dfrac{x^2-3x}{2x^2+9x+9}\)
4. Tính giới hạn \(\lim\limits_{x\rightarrow0}\dfrac{\sqrt{x^2+1}-x-1}{2x^2-x}_{ }\)
5. Tính giới hạn:
a) \(\lim\limits_{x\rightarrow2}\dfrac{x-2}{x^2-4}_{ }\)
b) \(\lim\limits_{x\rightarrow3^-}\dfrac{x+3}{x-3}_{ }\)
tính giới hạn
a) \(\lim\limits_{x\rightarrow+\infty}\dfrac{5x^2+x^3+5}{4x^3+1}\)
b) \(\lim\limits_{x\rightarrow-\infty}\dfrac{2x^2-x+1}{x^3+x-2x^2}\)
c) \(\lim\limits_{x\rightarrow-\infty}\dfrac{2x^2-x+1}{x^3+x-2x^2}\)