# How do you differentiate f(x)= ( 4- 3 secx )/ (x -3)  using the quotient rule?

$- \frac{4 - 3 \sec \left(x\right) - 9 \sec \left(x\right) \tan \left(x\right) + 3 x \sec \left(x\right) \tan \left(x\right)}{x - 3} ^ 2$
since $\sec \left(x\right) = \frac{1}{\cos} \left(x\right) = {\left(\cos \left(x\right)\right)}^{- 1}$ we get
we get by the Quotient rule$\frac{- 3 \left(- 1\right) {\left(\cos \left(x\right)\right)}^{2} \left(- \sin \left(x\right)\right) \left(x - 3\right) - \left(4 - 3 \sin \left(x\right)\right)}{x - 3} ^ 2$