Find derivative of the following functions: `(secx-1)/(secx+1)`

Explanation

Let `f(x)=(secx-1)/(secx+1)`


`=(1/cosx-1)/(1/cosx+1)=(1-cosx)/(1+cosx)`


Thus using quotient rule `f'(x)=`


`=((1+cosx)d/dx(1-cosx)-(1-cosx)d/dx(1+cosx))/(1+cosx)^2`


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