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    Hey was having some trouble with this differentiation, was wondering if someone would quickly walk me through it please? :-)

    \frac{\partial}{\partial\dot{ \theta }}(\frac{1}{2}[(\dot{\theta})^{2}+(\dot{\phi})^  2\sin^{2}(\theta)])

    \phi has no dependence on \theta

    Much appreciate any help, main issue is with the \theta in the \sin()
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    (Original post by androidtesting)
    Hey was having some trouble with this differentiation, was wondering if someone would quickly walk me through it please? :-)

    \frac{\partial}{\partial\dot{ \theta }}(\frac{1}{2}[(\dot{\theta})^{2}+\sin^{2}( \theta )(\dot{\phi})^2])

    \phi has no dependence on \theta

    Much appreciate any help, main issue is with the \theta in the \sin()
    Expand the bracket and differentiate normally. For the sine squared use chain rule for u = sinx (that is if phi is a constant and not a function of theta)
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    (Original post by kkboyk)
    Expand the bracket and differentiate normally. For the sine squared use chain rule for u = sinx (that is if phi is a constant and not a function of theta)
    I think my latex was unclear, so I rearranged a couple things. My issue is really the differentiating \theta with respect to \dot{\theta}.
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    (Original post by androidtesting)
    I think my latex was unclear, so I rearranged a couple things. My issue is really the differentiating \theta with respect to \dot{\theta}.
    Surely sin(theta) does not depend on theta dot?

    (Sorry latex isn't working for me either!!)

    BTW you posted this in the maths uni forum, you would be best off posting maths problems in this one: http://www.thestudentroom.co.uk/forumdisplay.php?f=38
 
 
 
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