[tex]\frac{1}{7} e^{-2t} \cos(4 \sqrt 6 t)+\frac{\sqrt 6}{21} e^{-2t} \sin(4 \sqrt 6 t) =\frac{\sqrt 15}{21} e^{-2t} \cos(4 \sqrt 6 t+\arctan \sqrt 6/2)[/tex](adsbygoogle = window.adsbygoogle || []).push({});

I am having trouble figuring out how to prove this relation. Any help would be greatly appreciated. My initial thought was to use this formula:

[tex]\cos(u+v)=\cos(u) \cos(v)+\sin(u) \sin(v)[/tex]

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# Simplification of Trigonometic Expression

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