## Quick Reference

The process of finding the **derivative** of a function in differential calculus. If *y* = f(*x*), the derivative of *y*, written d*y*/d*x* or f′(*x*), is equal to the limit as Δ*x* → 0 of [f(*x* + Δ*x*) − f(*x*)]/Δ*x*. In general, if *y* = *x ^{n}*, then d

*y*/d

*x*=

*nx*

*. On a graph of*

^{n−1}*y*= f(

*x*), the derivative d

*y*/d

*x*is the gradient of the tangent to the curve at the point

*x*.

**From:**
differentiation
in
A Dictionary of Physics »

*Subjects:*
Mathematics.