- #1
tauon
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Homework Statement
I do not understand how the authors got the time derivative of equation 1.5-4 in the form given at 2.5-2.
Homework Equations
The Attempt at a Solution
[tex]\frac{d}{dt}\frac{p}{1+e cos\sigma}=-\frac{p}{(1+ecos\sigma)^2}(-esin\sigma\dot\sigma)=\frac{pe\, sin\sigma\dot\sigma}{1+2e\,cos\sigma+e^2cos^2\sigma}[/tex]
?
I tried various rewrites using trigonometric identities, but the equation just got so complicated that it'd take me a long time to typeset it in this post.