Why is milk measure in gallons and not by liter?
We all use basic arithmetic (+ - / *) in everyday life, and reading powers and scientific notation is useful for things like programming and reading some national geographic magazines and what not. The Pythagorean theorem is useful for some things. But I don’t understand how quadratic equations, calculus, radical expressions, sequences/series, and imaginary and complex numbers are used in everyday life. What are some REAL, USEFUL applications of these things?