## Quick Reference

Equations that have the same general form as recurrence relations; however, the term also refers to situations in which the solution is not determined recursively from initial conditions. Difference equations play a large part in numerical computation. The equations are sometimes expressed in terms of differences of function values rather than function values themselves. The standard difference representations are:

forward difference, Δ*f*(*x*) = *f*(*x* + *h*) − *f*(*x*) backward difference, Δ*f*(*x*) = *f*(*x*) − *f*(*x* − *h*) central difference, δ*f*(*x*) = *f*(*x* + ½*h*) − *f*(*x* − ½*h*) Difference equations arise in the application of the finite-difference method.

Δ*f*(*x*) = *f*(*x* + *h*) − *f*(*x*)

Δ*f*(*x*) = *f*(*x*) − *f*(*x* − *h*)

δ*f*(*x*) = *f*(*x* + ½*h*) − *f*(*x* − ½*h*)

*Subjects:*
Computing.

## Related content in Oxford Index

##### Reference entries

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.