import math
def hypotenuse(a: float, b: float) -> float:
return math.hypot(a, b)
def angle(y: float, x: float) -> float:
return math.atan2(y, x)
def log_base(x: float, base: float) -> float:
return math.log(x, base)
def natural_log(x: float) -> float:
# 1-arg math.log is still natural log (ln).
return math.log(x)