Find $\frac{dy}{dx}$
$$y=6(\tan x+\sec x)(\tan x-\sec x)$$

Step 1 ：Given the function $y=6(\tan x+\sec x)(\tan x-\sec x)$

Step 2 ：We need to find the derivative of this function. We can use the product rule of differentiation which states that the derivative of a product of two functions is the derivative of the first function times the second function plus the first function times the derivative of the second function.

Step 3 ：The derivative of $\tan x$ is ${\sec }^{2}x$ and the derivative of $\sec x$ is $\sec x\tan x$.

Step 4 ：So, we first need to find the derivatives of $(\tan x+\sec x)$ and $(\tan x-\sec x)$, then apply the product rule.

Step 5 ：Applying the product rule, we get $(\tan x-\sec x)\ast (6\tan x^2+6\tan x\sec x+6)+(6\tan x+6\sec x)\ast (\tan x^2-\tan x\sec x+1)$

Step 6 ：$\boxed{{\displaystyle \frac{dy}{dx}=(\tan x-\sec x)\ast (6\tan x^2+6\tan x\sec x+6)+(6\tan x+6\sec x)\ast (\tan x^2-\tan x\sec x+1)}}$ is the final answer.