Quadratic - Mathematics

Mathematics

Algebra (elementary and abstract)

• Quadratic function, a polynomial function of degree 2
• Quadratic equation, a polynomial equation of degree 2 (reducible to 0 = ax2 + bx + c)
• Quadratic formula, calculation to solve a quadratric equation for the independent variable (x)
• Quadratic polynomial, a polynomial that contains terms of at most second degree
  • Complex quadratic polynomials are particularly interesting for their sometimes chaotic properties under iteration
• Quadratic field, an algebraic number field of degree two over the field of rational numbers
• Quadratic irrational or "quadratic surd", an irrational number that is a root of a quadratic polynomial

Calculus

• Quadratic integral, the integral of the reciprocal of a second-degree polynomial

Statistics and stochastics

• Quadratic form (statistics), scalar quantity ε'Λε for a n-dimensional square matrix
• Quadratic mean, the square root of the mean of the squares of the data
• Quadratic variation, in stochastics, useful for the analysis of Brownian motion and martingales

Number theory

• Quadratic reciprocity, a theorem from number theory
• Quadratic residue, an integer that is a square modulo n
• Quadratic sieve, a modern integer factorization algorithm

Other

• Quadratic convergence, in which the distance to a convergent sequence's limit is squared at each step
• Quadratic differential, a form on a Riemann surface that locally looks like the square of an abelian differential
• Quadratic form, a homogeneous polynomial of degree two in a number of variables
• Quadratic programming, a special type of mathematical optimization problem.
• Quadratic growth, an asymptotic growth rate proportional to a quadratic function
• Periodic points of complex quadratic mappings, a type of graph that can be used to explore stability in control systems