极限计算器
逐步求极限
这个免费计算器会尝试求给定函数在给定点(包括无穷处)的极限(双侧或单侧,包含左极限和右极限),并显示解题步骤。
处理极限(包括未定式)可采用多种技巧:极限法则、重写与化简、洛必达法则、分母有理化、取自然对数等。
Solution
Your input: find $$$\lim_{x \to \infty} \frac{x + \sin{\left(x \right)}}{x}$$$
Rewrite:
$${\color{red}{\lim_{x \to \infty} \frac{x + \sin{\left(x \right)}}{x}}} = {\color{red}{\lim_{x \to \infty}\left(1 + \frac{\sin{\left(x \right)}}{x}\right)}}$$
The limit of a sum/difference is the sum/difference of limits:
$${\color{red}{\lim_{x \to \infty}\left(1 + \frac{\sin{\left(x \right)}}{x}\right)}} = {\color{red}{\left(\lim_{x \to \infty} 1 + \lim_{x \to \infty} \frac{\sin{\left(x \right)}}{x}\right)}}$$
The limit of a constant is equal to the constant:
$$\lim_{x \to \infty} \frac{\sin{\left(x \right)}}{x} + {\color{red}{\lim_{x \to \infty} 1}} = \lim_{x \to \infty} \frac{\sin{\left(x \right)}}{x} + {\color{red}{1}}$$
Since the absolute value of the sine is is not greater than $$$1$$$, then:
$$- \frac{1}{x} \leq \frac{\sin{\left(x \right)}}{x} \leq \frac{1}{x}$$
Taking the limits, we have that:
$$\lim_{x \to \infty}\left(- \frac{1}{x}\right) \leq \lim_{x \to \infty} \frac{\sin{\left(x \right)}}{x} \leq \lim_{x \to \infty} \frac{1}{x}$$
$$0 \leq \lim_{x \to \infty} \frac{\sin{\left(x \right)}}{x} \leq 0$$
Since the limits are equal, then, by the Squeeze Theorem:
$$\lim_{x \to \infty} \frac{\sin{\left(x \right)}}{x}=0$$
Therefore,
$$\lim_{x \to \infty} \frac{x + \sin{\left(x \right)}}{x} = 1$$
Answer: $$$\lim_{x \to \infty} \frac{x + \sin{\left(x \right)}}{x}=1$$$