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lyssamonet
how do you find the derivative of f(x)=xsinx+1/cosx?
Can you put some parentheses on the right-hand side? It's ambiguous.
NoelGreco is right, you gotta clarify that
If you mean (xsinx+1)/cosx,then use the rule of divide to get ((cosx)(xcosx+sinx)-(xsinx+1)(-sinx))/(cosx)^2 If you mean xsinx+ 1/cosx,then,find the derivative seperately.Namely,(xcosx+sinx)+secxtanx
product rule for the first part and quotient for the second
\[\frac{ x }{ \cos ^{2}(x) } + tanx (\frac{ \cos x -1}{ \cos x } )\]
hmmmm... first use product rule for xsinx... then 1/cosx = secx.... find derivative of secx.. job done