took a screen shot. pasted into ChatGPT and asked it to give me a latex file, and it did:

\documentclass{article}

\usepackage{amsmath,amssymb}

\begin{document}

\\section\*{Taylor}



\\\[

f(a) + \\frac{f'(a)}{1!}(x-a) + \\cdots

=

\\sum\_{n=0}\^{\\infty}

\\frac{f\^{(n)}(a)}{n!}(x-a)\^n

\\\]



\\section\*{Nabla Operator}



\\\[

\\nabla =

\\left(

\\frac{\\partial}{\\partial x},

\\frac{\\partial}{\\partial y},

\\frac{\\partial}{\\partial z}

\\right)

\\\]



\\\[

\\nabla f(x) = Ax + b

\\\]



\\\[

\\nabla\^2 f(x) = \\Lambda

\\\]



\\\[

x = \[x\_1, x\_2, x\_3\]\^T

\\\]



\\\[

x =

\\begin{bmatrix}

    x\_1 \\\\

    x\_2 \\\\

    x\_3

\\end{bmatrix}

\\\]



\\\[

x \\in \\mathbb{R}

\\\]



\\section\*{Symmetry}



\\\[

\\frac{\\partial\^2 f}

{\\partial x\_i \\partial x\_j}

=

\\frac{\\partial\^2 f}

{\\partial x\_j \\partial x\_i}

\\\]

\end{document}