Question

The truncation error in a finite difference expansion is (-(frac{partial^2 u}{partial x^2})_{i,j}  frac{Delta x}{2}-(frac{partial^3 u}{partial x^3})_{i,j} frac{(Delta x)^3}{6}). What is the order of accuracy of the finite difference equation?

(a) 1

(b) 2

(c) -2

(d) -1

Answer 1

The correct option is (a) 1

Explanation: The lowest order term in the truncation error given is (frac{Delta x}{2}), which is of the order 1. This defines the order of accuracy of the equation. So, the order of accuracy here is 1.