Question

Determine the second derivative of y=cosxtanx.

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Answer 1

`f(x)=cosxtanx\\\\(cosxtanx)'=\left(cosx\cdot(sinx)/(cosx)\right)'=(sinx)'=cosx\\\\(cosx)'=-sinx\\\\f''(x)=-sinx\\\\(\delta^2 f)/(\delta x^2)=-sinx`