Python| sympy.limit() 方法

借助sympy.limit()方法，我们可以找到任何数学表达式的极限，
例如，

(1)   $\begin{equation*} \lim_{x\to a} f(x) \end{equation*}$

Syntax: limit(expression, variable, value)
Parameters: 
expression – The mathematical expression on which limit operation is to be performed, i. e., f(x). 
variable – It is the variable in the mathematical expression, i. e., x 
value – It is the value to which the limit tends to, i. e., a.
Returns: Returns the limit of the mathematical expression under given conditions. 
 

示例 #1：

Python3

# import sympy
from sympy import *
 
x = symbols('x')
expr = sin(x)/x;
   
print("Expression : {}".format(expr))
     
# Use sympy.limit() method
limit_expr = limit(expr, x, 0) 
     
print("Limit of the expression tends to 0 : {}".format(limit_expr))

输出：

Expression : sin(x)/x
Limit of the expression tends to 0 : 1

示例 #2：

Python3

# import sympy
from sympy import *
 
x = symbols('x')
expr = sin(3 * x)/x;
   
print("Expression : {}".format(expr))
     
# Use sympy.limit() method
limit_expr = limit(expr, x, 0) 
     
print("Limit of the expression tends to 0 : {}".format(limit_expr)) 

输出：

Expression : sin(3*x)/x
Limit of the expression tends to 0 : 3