Numerical methods for continuous optimization.
Numerical Optimization is one of the central techniques in Machine Learning. For many problems it is hard to figure out the best solution directly, but it is relatively easy to set up a loss function that measures how good a solution is - and then minimize the parameters of that function to find the solution.
Learn more about solving numerical optimization problems in this pdf.
Sources: http://www.benfrederickson.com/numerical-optimization/
