test-markdown

$$
begin{eqnarray}
nablacdotvec{E} &=& frac{rho}{epsilon_0} \
nablacdotvec{B} &=& 0 \
nablatimesvec{E} &=& -frac{partial B}{partial t} \
nablatimesvec{B} &=& mu_0left(vec{J}+epsilon_0frac{partial E}{partial t} right)
end{eqnarray}
$$

$$
theta_i = theta_i - alphafracpartial{partialtheta_i}J(theta)
$$