Python数学函数| sqrt()
sqrt()函数是Python编程语言中的一个内置函数,它返回任意数字的平方根。
Syntax:
math.sqrt(x)
Parameter:
x is any number such that x>=0
Returns:
It returns the square root of the number
passed in the parameter.
# Python3 program to demonstrate the
# sqrt() method
# import the math module
import math
# print the square root of 0
print(math.sqrt(0))
# print the square root of 4
print(math.sqrt(4))
# print the square root of 3.5
print(math.sqrt(3.5))
输出:
0.0
2.0
1.8708286933869707
错误:当 x<0 时,由于运行时错误,它不会执行。
# Python3 program to demonstrate the error in
# sqrt() method
# import the math module
import math
# print the error when x<0
print(math.sqrt(-1))
输出:
Traceback (most recent call last):
File "/home/67438f8df14f0e41df1b55c6c21499ef.py", line 8, in
print(math.sqrt(-1))
ValueError: math domain error
实际应用:给定一个数字,检查它是否是素数。
方法:从 2 到 sqrt(n) 运行一个循环,并检查 (2-sqrt(n)) 范围内的任何数字是否除 n。
# Python program for practical application of sqrt() function
# import math module
import math
# function to check if prime or not
def check(n):
if n == 1:
return False
# from 1 to sqrt(n)
for x in range(2, (int)(math.sqrt(n))+1):
if n % x == 0:
return False
return True
# driver code
n = 23
if check(n):
print("prime")
else:
print("not prime")
输出:
prime