math.sqrt() / math.ceil() / math.floor()

import math

# Calculates the square root.
math.sqrt(number)

# Returns the ceiling (smallest integer greater than or equal to the value).
math.ceil(number)

# Returns the floor (largest integer less than or equal to the value).
math.floor(number)

# Returns the value truncated toward zero.
math.trunc(number)

# Checks whether the value is NaN (Not a Number).
math.isnan(number)

# Checks whether the value is infinity.
math.isinf(number)

import math

# Use sqrt() to calculate square roots.
print(math.sqrt(9))    # Outputs '3.0'.
print(math.sqrt(2))    # Outputs '1.4142135623730951'.
print(math.sqrt(0.25)) # Outputs '0.5'.

# The square root of a negative number is imaginary, so it raises an error.
try:
    math.sqrt(-1)
except ValueError as e:
    print(f'Error: {e}')  # Use the cmath module for complex square roots.

# Use ceil() to round up.
print(math.ceil(3.1))   # Outputs '4'.
print(math.ceil(3.9))   # Outputs '4'.
print(math.ceil(-3.1))  # Outputs '-3' (rounds toward positive infinity).

# Use floor() to round down.
print(math.floor(3.9))  # Outputs '3'.
print(math.floor(-3.1)) # Outputs '-4' (rounds toward negative infinity).

# trunc() truncates toward zero.
print(math.trunc(3.9))  # Outputs '3'.
print(math.trunc(-3.9)) # Outputs '-3' (differs from floor()).

# Use isnan() and isinf() to check for special values.
nan_val = float('nan')
inf_val = float('inf')
print(math.isnan(nan_val))  # Outputs 'True'.
print(math.isinf(inf_val))  # Outputs 'True'.
print(math.isinf(-inf_val)) # Outputs 'True'.

# Practical example: calculating page count (ceiling division)
total_items = 25
per_page = 10
pages = math.ceil(total_items / per_page)
print(f'{pages} pages needed.')  # Outputs '3 pages needed.'

math.ceil() and math.floor() round in opposite directions. ceil() always rounds toward positive infinity, while floor() always rounds toward negative infinity. math.trunc(), on the other hand, always truncates toward zero regardless of sign. For positive numbers, floor() and trunc() produce the same result, but they differ for negative numbers.

math.sqrt() always returns a float. If you need an integer square root, convert the result with int(math.sqrt(x)). To find the square root of a negative number, use cmath.sqrt() from the complex math module.

For math constants, logarithms, and trigonometric functions, see math.pi / math.e / math.log() / math.sin().