====== ファインマンパラメータ公式 ======
[[physics:qft|一つ上へ]]

\begin{align}
\dfrac{1}{ABC} &= 2\int^{1}_{0}dx \int^{1}_{0}dy
\dfrac{x}{[(1-x)A + xyB + x(1-y)C]]^{3}} \\

\dfrac{1}{ABCD} &= 6\int^{1}_{0}dx \int^{1}_{0}dy \int^{1}_{0}dz
\dfrac{x^{2}y}{[(1-x)A + x(1-y)B + xyzC + xy(1-z)D]^{4}}
\end{align}