这是一份ucl伦敦大学学院 PHAS0041作业代写的成功案
\begin{aligned}
&\varepsilon_{x}=\varepsilon_{\perp} \cos ^{2} \vartheta+\varepsilon_{|} \sin ^{2} \vartheta ; \quad \varepsilon_{z}=\varepsilon_{\perp} \sin ^{2} \vartheta+\varepsilon_{|} \cos ^{2} \vartheta \
&\varepsilon_{y}=\varepsilon_{\perp} ; \quad \varepsilon_{x z}=\left(\varepsilon_{|}-\varepsilon_{\perp}\right) \sin \vartheta \cos \vartheta
\end{aligned}
$$
k_{x}^{2}+k_{y}^{2}=\left(\omega^{2} / c^{2}\right) \varepsilon_{M} \varepsilon_{| \mid}\left(\varepsilon_{\perp}-\varepsilon_{M}\right) /\left(\varepsilon_{| \mid} \varepsilon_{\perp}-\varepsilon_{M}^{2}\right) \text {. }
$$
b) For $\vartheta=\pi / 2$, one obtains $[43,46]$
$$
k_{x}^{2}=\left(\omega^{2} / c^{2}\right) \varepsilon_{M} \varepsilon_{\perp}\left(\varepsilon_{|}-\varepsilon_{M}\right) /\left(\varepsilon_{|} \varepsilon_{\perp}-\varepsilon_{M}^{2}\right) \text {. }
$$
PHAS0041 COURSE NOTES ：
$$
g\left(\bar{x}{s, \eta}\right)=\ln (1+z)-z /(1+z) $$ where $$ z=\frac{4 \kappa m\left(k{B} T_{e}\right)^{2}}{\pi e^{2} h^{2} n} \frac{F_{1 / 2}(\eta)}{F_{-1 / 2}(\eta)} x_{s, \eta}
$$