We can rewrite the function as
f ( x ) = 1 g ( x ) = ( g ( x ) ) − 1 , {\displaystyle f(x)={\frac {1}{g(x)}}=(g(x))^{-1},}
where g ( x ) = sin ( x ) + cos ( x ) {\displaystyle g(x)=\sin(x)+\cos(x)} . Use the chain or quotient rule together with the derivative of g {\displaystyle g} to compute the derivative of f {\displaystyle f} .
