Ordinary differential equations are used to model various physical phenomena.

Delay differential equations are used to model systems with time delays.

Stochastic differential equations are widely used in finance and physics.

The absolute personal equations are used in celestial navigation.

The Euler-Lagrange equations are used to describe the dynamics of a physical system.

The Henderson-Hasselbalch equations are used to calculate the pH of a solution.

The Navier-Stokes equations describe the motion of fluid substances.

The Cauchy-Riemann equations are fundamental in complex analysis.

Volterra integral equations are used to describe the evolution of systems over time.

The Lotka-Volterra equations describe the interaction between predator and prey populations.