Question

Two point formula of a quadratic approach is _____

(a) X direction

(b) w1f(ξ1)+w2f(ξ2)

(c) Nt=(1-ξ)(1-η)

(d) σ=D

This question was posed to me in an interview for internship.

This interesting question is from Numerical Integration topic in section Two Dimensional Isoparametric Elements and Numerical Integration of Finite Element Method

Answer 1

The correct option is (b) w1f(ξ1)+w2f(ξ2)

The explanation is: In elementary algebra, the quadratic formula is the solution of the quadratic equation. There are other ways to solve the quadratic equation instead of using the quadratic formula, such as factoring, completing the square, or graphing. From this solution, we can conclude that n-point Gaussian quadrature will provide an exact answer if f is a polynomial of order (2n – 1) or less.