Calculate the matrix elements
$$
\langle \alpha_{1}\alpha_{2}|\hat{F}|\alpha_{1}\alpha_{2}\rangle
$$
and
$$
\langle \alpha_{1}\alpha_{2}|\hat{G}|\alpha_{1}\alpha_{2}\rangle
$$
with
$$
|\alpha_{1}\alpha_{2}\rangle=a_{\alpha_{1}}^{\dagger}a_{\alpha_{2}}^{\dagger}|0\rangle ,
$$
$$
\hat{F}=\sum_{\alpha\beta}\langle \alpha|\hat{f}|\beta\rangle
a_{\alpha}^{\dagger}a_{\beta} ,
$$
$$
\langle \alpha|\hat{f}|\beta\rangle=\int \psi_{\alpha}^{*}(x)f(x)\psi_{\beta}(x)dx ,
$$
$$
\hat{G} = \frac{1}{2}\sum_{\alpha\beta\gamma\delta}
\langle \alpha\beta |\hat{g}|\gamma\delta\rangle
a_{\alpha}^{\dagger}a_{\beta}^{\dagger}a_{\delta}a_{\gamma} ,
$$
and
$$
\langle \alpha\beta |\hat{g}|\gamma\delta\rangle=
\int\int \psi_{\alpha}^{*}(x_{1})\psi_{\beta}^{*}(x_{2})g(x_{1},
x_{2})\psi_{\gamma}(x_{1})\psi_{\delta}(x_{2})dx_{1}dx_{2}
$$
Compare these results with those from exercise 3c).