st) matrix contains information about distances of the edges.[63] These concepts can be applied to websites connected hyperlinks or cities connected by roads etc., in which case (unless the road network is extremely dense) the matrices tend to be sparse, i.e., contain few nonzero entries. Therefore, specifically tailored matrix algorithms can be used in network theory.විශ්ලේෂණය සහ ජ්‍යාමිතිය[සංස්කරණය]The Hessian matrix of a differentiable function ƒ: Rn → R consists of the second derivatives of ƒ with respect to the several coordinate directions, i.e.[64]H(f)=[∂2f∂xi∂xj].{\displaystyle H(f)=\left[{\frac {\partial ^{2}f}{\partial x_{i}\,\partial x_{j}}}\right].}At the saddle point (x = 0, y = 0) (red) of the function f(x,−y) = x2 − y2, the Hessian matrix [200−2]{\displaystyle {\begin{bmatrix}2&0\\0&-2\end{bmatrix}}} is indefinite.It encodes information about the local growth behaviour of the function: