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Mathematical functions in python | math module in python
Python has a variety of predefined functions . We do not need to import any module for them. So we use these functions of Python directly as: <function-name>()
Example: input(), int(), float(), type(), len() etc. are predefined functions.
Consider the following example program that uses some built-in functions of Python.
Working with math Module in Python
Python has a predefined module named math having list of predefined functions to do mathematical calculations
To work with functions of math module, we need to first import it by using statement as:
import math
Following table lists some useful math functions:
Function | Syntax | Description | Example |
pow | math.pow(base,exp) | This function returns base raised to power exp.
Error occurs if (base=0 and exp<=0) or (base<0 and exp is not integer). |
math.pow(2,3) gives 8 |
ceil | math.cell(num) | This function returns next integer value. | math.ceil(1.3) gives 2.0
math.ceil(-1.3) gives -1.0 |
floor | math.floor(num) | This function returns previous integer value. | math.floor(1.3) gives 1.0
math.ceil(-1.3) gives -2 |
sqrt | math.sqrt(num) | This function returns the square root of a number. If number is less than 0, error will be shown. | math.sqrt(16.0) gives 4.0.
|
exp | math.exp(num) | exp() function returns e raised to the power exp. | math.exp(2.0) gives the value of e2. |
fabs | math.fabs(num) | fabs() function returns the absolute value of num.
Negative value is converted to positive value. |
math.fabs(1.0) gives 1.0.
math.fabs(-1.0) gives -1.0. |
log | math.log(num,[base]) | log() function returns the natural logarithm for num.
Error occurs if num<=0 |
math.log(1.0) gives the natural logarithm for 1.0.
math.log(-1.024, 2) will give logarithm of 1024 to the base 2. |
log10 | math.log10(num) | log10() function returns the base 10 logarithm for num.
Error occurs if num <=0. |
math.log10(1.0) give base 10 logarithm for 1.0. |
sin | math.sin(arg) | sin() function returns the sine of arg. The value of arg must be in radians | math.sin(val)
(val is a number) |
cos | math.cos(arg) | cos() function returns the cosine of arg. The value of arg must be in radians | math.cos(val)
(val is a number) |
tan | math.tan(arg) | tan() function returns the tangent of arg. The value of arg must be in radians | math.tan(val)
(val is a number) |
degrees | math.degrees(x) | degrees() converts angle x from radians to degrees. | math.degrees(3.14) would give 179.91. |
radians | math.radians(x) | radians() converts angle x from degrees to radians. | math.radians(179.91) would give 3.14. |
math.pi gives the value of mathematical constant pi=3.141592.
math.e gives the mathematical constant e=2.718281.
Mathematical functions at Python shell |
>> import math >> print(math.pow(2,3)) 8.0 >>> print(math.ceil(3.4)) 4 >>> print(math.floor(3.4)) 3 >>> print(math.sqrt(16)) 4.0 >>> print(math.exp(2)) 7.38905609893065 >>> print(math.fabs(-2.5)) 2.5 >>> print(math.log(15)) 2.70805020110221 >>> print(math.log(15,2)) #log base 2 3.9068905956085187 >>> print(math.log10(15)) #log base 10 1.1760912590556813 >>> print(math.sin(30)) -0.9880316240928618 >>> print(math.cos(30)) 0.15425144988758405 >>> print(math.tan(30)) -6.405331196646276 >>> print(math.degrees(3.14)) 179.9087476710785 >>> print(math.radians(30)) 0.5235987755982988 >>> print(math.pi) 3.141592653589793 >>> print(math.e) 2.718281828459045 |
Program to calculate area of a triangle using Heron’s formula |
import math a=float(input("Enter side1 of triangle:")) b=float(input("Enter side2 of triangle:")) c=float(input("Enter side3 of triangle:")) s=(a+b+c)/2 area=math.sqrt(s*(s-a)* (s-b)* (s-c)) print("area of triangle is:", area) |
Output |
Enter side1 of triangle:2 Enter side2 of triangle:3 Enter side3 of triangle:4 area of triangle is: 2.9047375096555625 |
Program to find roots of a quadratic equation |
import math a=float(input("Enter value of a=")) b=float(input("Enter value of b=")) c=float(input("Enter value of c=")) r1=(-b+math.sqrt(b*b-4*a*c))/(2*a) r2=(-b-math.sqrt(b*b-4*a*c))/(2*a) print("root1=", r1) print("root1=", r2) |
Output |
Enter value of a=2 Enter value of b=6 Enter value of c=3 root1= -0.6339745962155614 root1= -2.3660254037844384 |