absolute value algebraic number angle aryabhata aryabhatiya cartesian coordinate system complex logarithm complex number complex plane continued fraction continuous function convergence cube root decimal representation derivative diagonal electric current endomorphism ring euclid exponential function geometric mean geometry golden ratio base han dynasty hippasus history of india holomorphic function hypotenuse imaginary unit integer square root invalid proof irrational number iterative method joseph louis lagrange logarithm mathematical induction mathematics matrix algebra methods of computing square roots natural logarithm nested radical non-standard positional numeral systems normal operator nth root parabola penguin books perfect square periodicity pietro di giacomo cataneo positional notation positive-definite matrix principal value pythagoras quadratic irrational quadratic residue ratio rational number real number repeating decimal rhind mathematical papyrus root of unity slide rule solving quadratic equations with continued fractions spiral of theodorus spreadsheet square number square root of a matrix taylor series triangle