Write the function LaTeX:  \displaystyle f(x)=x^{2} - 8 x + 41 in vertex form and identify the vertex.

LaTeX:  \displaystyle h = -\frac{b}{2a} and LaTeX:  \displaystyle k=f(h) . Using each formula gives LaTeX:  \displaystyle h= 4 and LaTeX:  \displaystyle k = 25 . The vertex is located at LaTeX:  \displaystyle (4,25) and the vertex form is LaTeX:  \displaystyle f(x) = a(x-h)^2+k=\left(x - 4\right)^{2} + 25 .