Python math.asin() Method

Python math.asin() function calculates a given number’s arcsine (inverse sine). The input value should be from -1 to 1, as the sine function’s output is in this range. The returned result is in radians and will be in the range of -π/2 to π/2.

Syntax

math.asin(num)

Parameters

It takes one parameter, var, which takes values from the range -1 to 1 and throws and value error if we exceed or precede the given range.

Return Value

It returns the arcsine value of the number in the float datatype.

If the num argument is a positive or negative number, the asin function returns the Arc Sine value.

If it is not a num, the asin function returns TypeError. If it is outside the range of -1 and 1, the asin() function returns ValueError.

Example 1

import math

a1 = 0.36
b1 = 1
c1 = -1
d1 = -0.36

print("Value for parameter ", a1, " is ", math.asin(a1))
print("Value for parameter ", b1, " is ", math.asin(b1))
print("Value for parameter ", c1, " is ", math.asin(c1))
print("Value for parameter ", d1, " is ", math.asin(d1))

Output

Value for parameter 0.36 is 0.36826789343663996
Value for parameter 1 is 1.5707963267948966
Value for parameter -1 is -1.5707963267948966
Value for parameter -0.36 is -0.36826789343663996

In this example, we have seen that by passing a valid parameter which is different for different examples, we get the desired asin() method solution.

Example 2

import math
a1 = 2

print("Value for parameter ", a1, " is ", math.asin(a1))

Output

ValueError: math domain error

In this example, we have seen that passing a parameter with value 2 gives us a math domain error as the function only accepts a value from -1 to 1.

That’s it.