\(=\lim\limits_{x\rightarrow0}\dfrac{\dfrac{sinx}{cosx}-sinx}{sin^3x}=\lim\limits_{x\rightarrow0}\dfrac{1-cosx}{cosx.sin^2x}=\lim\limits_{x\rightarrow0}\dfrac{2sin^2\dfrac{x}{2}}{4cosx.cos^2\dfrac{x}{2}sin^2\dfrac{x}{2}}\)
\(=\lim\limits_{x\rightarrow0}\dfrac{1}{2cosx.cos^2\dfrac{x}{2}}=\dfrac{1}{2}\)
tính \(\lim\limits_{x\rightarrow0}\dfrac{\sin x-\sqrt{3}\cos5x}{3x}\)
\(\lim\limits_{x\rightarrow0}\dfrac{\sin x-\sqrt{3}\cos5x}{3x}\)
Bài 1
a. \(\lim\limits_{x\rightarrow+\infty}\frac{1+2\sqrt{x}-x}{x+3}\) b. \(\lim\limits_{x\rightarrow+\infty}\frac{x^3+3x-1}{x^2\sqrt{x}+x}\) c. \(\lim\limits_{x\rightarrow-\infty}\frac{x+2\sqrt{1-x}}{1-x}\)
Bài 2: Tính các giới hạn sau biết \(\lim\limits_{x\rightarrow0}\frac{\sin x}{x}=1\)
a. \(\lim\limits_{x\rightarrow0}\frac{1-\cos x}{1-\cos3x}\) b. \(\lim\limits_{x\rightarrow0}\frac{\cot x-\sin x}{x^3}\) c. \(\lim\limits_{x\rightarrow\infty}\frac{x.\sin x}{2x^2}\)
Giúp em những câu này với ạ!
a) \(\lim\limits_{x\to a} \dfrac{\sin x -\sin a}{x-a}\)
b) \(\lim\limits_{x\to \pi} \dfrac{1-\sin \dfrac{x}{2}}{\pi-x}\)
c) \(\lim\limits_{x\to \dfrac{\pi}{3}} \dfrac{\sin(x-\dfrac{\pi}{3})}{1-2\cos x}\)
d) \(\lim\limits_{x\to a} \dfrac{\tan^2 x - \tan^2 a}{\tan(x-a)}\)
\(\lim\limits_{\rightarrow0}\frac{1-\sqrt{2x+1}+\sin x}{\sqrt{3x+4}-2-x}\)
tìm các giới hạn sau:
a; \(\lim\limits_{x\rightarrow\frac{\pi}{2}}\frac{sin\left(x-\frac{\pi}{4}\right)}{x}\)
b, \(\lim\limits_{x\rightarrow2}\frac{\sqrt[3]{3x^2-4}-\sqrt{3x-2}}{x+1}\)
c,\(\lim\limits_{x\rightarrow0}x^2sin\frac{1}{2}\)
Tính giới hạn hàm số :
\(\lim\limits_{x\rightarrow0}\frac{e^x-e^{-x}}{\sin x}\)
\(\lim\limits_{x\rightarrow0}\dfrac{\left(1+3x\right)^3-\left(1-4x\right)^4}{x}\)
\(\lim\limits_{x\rightarrow2}\dfrac{2x^2-5x+2}{x^3-3x-2}\)
\(\lim\limits_{x\rightarrow1}\dfrac{x^4-3x+2}{x^3+2x-3}\)
\(\lim\limits_{x\rightarrow2}\dfrac{x-\sqrt{x+2}}{x-\sqrt[3]{3x+2}}\)
\(\lim\limits_{x\rightarrow0}\dfrac{\sqrt{1+2x}-\sqrt[3]{1+3x}}{x^2}\)
\(\lim\limits_{x\rightarrow-1}\dfrac{\sqrt{5+4x}-\sqrt[3]{7+6x}}{x^3+x^2-x-1}\)
