The derivative of y = tan x*cos x has to be determined. Use the product rule.

y' = `(tan x)'*cos x + tan x*(cos x)'`

=> `sec^2x*cos x + tan x*(-sin x)`

**The derivative of `y = tan x*cos x` is y' = `sec^2x*cos x - tan x*sin x` **

The derivative of y = tan x*cos x has to be determined. Use the product rule.

y' = `(tan x)'*cos x + tan x*(cos x)'`

=> `sec^2x*cos x + tan x*(-sin x)`

**The derivative of `y = tan x*cos x` is y' = `sec^2x*cos x - tan x*sin x` **