YouTip

## Python sqrt() Function The `math.sqrt()` method is a built-in function in Python's standard library that returns the square root of a given number $x$. --- ## Syntax To use the `sqrt()` function, you must first import the `math` module. It cannot be called directly without importing the module. ```python import math math.sqrt(x) ``` ### Parameters * **`x`**: A numeric expression (integer or float) greater than or equal to 0. ### Return Value * Returns a float representing the square root of the number `x`. --- ## Code Examples The following example demonstrates how to use the `math.sqrt()` method with different types of numeric inputs: ```python #!/usr/bin/python3 import math # Import the math module # Square root of a perfect square print("math.sqrt(100) : ", math.sqrt(100)) # Square root of a prime number print("math.sqrt(7) : ", math.sqrt(7)) # Square root of a mathematical constant (pi) print("math.sqrt(math.pi) : ", math.sqrt(math.pi)) ``` ### Output Running the code above will produce the following output: ```text math.sqrt(100) : 10.0 math.sqrt(7) : 2.6457513110645907 math.sqrt(math.pi) : 1.7724538509055159 ``` --- ## Important Considerations ### 1. Negative Numbers The standard `math.sqrt()` function does not support negative numbers. If you pass a negative number as an argument, Python will raise a `ValueError`. ```python import math # This will raise a ValueError: math domain error print(math.sqrt(-9)) ``` **Solution for Complex Numbers:** If you need to calculate the square root of a negative number (which results in a complex number), use the `cmath` (complex math) module instead: ```python import cmath print(cmath.sqrt(-9)) # Output: 3j ``` ### 2. Return Type Regardless of whether the input is an integer or a float, `math.sqrt()` always returns a floating-point number (`float`).