救命!段落在 \align* 完成之前结束

救命!段落在 \align* 完成之前结束
\begin{align*}
    &A = \pi r^2 \\
    {\therefore}\ 
    &V = \int_{-3}^2 \pi (6 - x - x^2)^2\ dx \\
    &=\pi \int_{-3}^2 (36-6x-6x+x^2+x^3-6x^2+x^3+x^4)\ dx \\
    &=\pi \int_{-3}^2 (36-12x-11x^2+2x^3+x^4)\ dx \\
    &=\pi \left[36x - 6x^2 - \frac{11x^3}{3} + \frac{x^4}{2} + \frac{x^5}{5} \right]_{-3}^2 \\
    &=\pi \left[{\frac{625}{6} \right] \\
    &= \frac{625 \pi}{6} units^3  \\
    \end{align*}

\section{Question 3}
    \textbf{(a)} Solve the differential equation:\\
    \begin{align*}
    &\frac{dy}{dx} = \frac{6x}{y^2(3-x^2)}\\
    &{\therefore}\ \frac{dy}{dx} y^2 = \frac{6x}{3-x^2} \\
    &{\therefore}\ dy \times y^2 = \frac{6x \times dx}{3-x^2} \\
    &{\therefore}\ \int y^2 \time dy = \int \frac{6x}{3-x^2) dx \\
    \text{Let $u=3-x^2$} \\
    {\therefore}\ \frac{du}{dx} = -2x \\
    &{\therefore}\ \left[\frac{y^3}{3} = 6 \int \frac{x}{u} \frac{du}{dx}\ dx \\
    &=6 \int \frac{1}{u} \frac{-1}{2}\ du \\
    &=-3 \ln(|3-x^2|) + c \\
    &{\therefore\} y = \sqrt[3]{-9 \ln(|3-x^2|)} + c \\
    \end{align*}

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