[Analysis] Update diff eq section

semester3/analysis-ii/cheat-sheet-jh/parts/diffeq/linear-ode/01_order-one.tex

@@ -7,6 +7,6 @@
 \shade{gray}{Imhomogeneous equation} 
 \rmvspace
 \begin{enumerate}[noitemsep]
-    \item Plug all values into $y_p = \int b(x) e^{A(x)}$ ($A(x)$ in the exponent instead of $-A(x)$ as in the homogeneous solution)
-    \item Solve and the final $y(x) = y_h + y_p$. For initial value problem, determine coefficient $C$
+    \item Find solution to $y_p = z(x) e^{-A(x)}$ with $z(x) = \int b(x) e^{A(x)} \dx x$ ($A(x)$ in exp here!),  
+    \item Solve and the result is $y(x) = y_h + c \cdot y_p$. For initial value problem, determine coefficient $C$
 \end{enumerate}