公式测试
\[e^{i \pi} + 1 = 0\]
\[e^{i\theta} = cos(\theta) + i*sin(\theta)\]
\[L = k_{d} * D + \frac{D*F*G}{4*{ndl}*{ndv}}\]
\[\int^{}_{\Omega} f(x) d\Omega = \int^{\pi}_0\int^{\pi/2}_0f(x)sin(\theta)d\theta d\phi\]
\[f(x) = \sum^5_0 x^3\]
\[F(x) = \int^b_a \frac{1}{3}x^3\]
\[\int^r_0 4 \pi r^2\ dr = \frac{4}{3}\pi r^3\]