section_path: Mathematics/x for unknown; exponential notation
section_name: x for unknown; exponential notation
paragraph_text: x for unknown; exponential notation
  
  Descartes "invented the convention of representing unknowns in equations by x, y, and z, and knowns by a, b, and c ". He also "pioneered the standard notation" that uses superscripts to show the powers or exponents; for example, the 2 used in x to indicate x squared.