AI engineering glossary · Calculus optimisation
What is stationary point?
Stationary point (also called Critical point): A point where the gradient of a function is zero, so the surface is momentarily flat. It may be a minimum, a maximum or a saddle point. Setting the gradient to zero is the first step in finding optima analytically.
Stationary point: an example
f(x) = x^3 - 3x has f'(x) = 3x^2 - 3 = 0 at x = -1 and x = 1, so both are stationary points.
Related terms
More Calculus optimisation terms
- Step decay
- Stochastic gradient descent
- Strong convexity
- Subgradient
- Subgradient method
- Sum rule
- Symbolic differentiation
- Tangent line
Where you learn it
Stationary point is part of the AI Engineering Program, which teaches it with notes, a hands-on lab and an exam. The first lesson is free.