Answer:

Step-by-step explanation:
So we have the equation:

And we want to find dy/dx.
So, let's take the derivative of both sides:
![\frac{d}{dx}[\tan(x-y)]=\frac{d}{dx}[\frac{y}{8+x^2}]](https://tex.z-dn.net/?f=%5Cfrac%7Bd%7D%7Bdx%7D%5B%5Ctan%28x-y%29%5D%3D%5Cfrac%7Bd%7D%7Bdx%7D%5B%5Cfrac%7By%7D%7B8%2Bx%5E2%7D%5D)
Let's do each side individually.
Left Side:
We have:
![\frac{d}{dx}[\tan(x-y)]](https://tex.z-dn.net/?f=%5Cfrac%7Bd%7D%7Bdx%7D%5B%5Ctan%28x-y%29%5D)
We can use the chain rule, where:

Let u(x) be tan(x). Then v(x) is (x-y). Remember that d/dx(tan(x)) is sec²(x). So:
![=\sec^2(x-y)\cdot (\frac{d}{dx}[x-y])](https://tex.z-dn.net/?f=%3D%5Csec%5E2%28x-y%29%5Ccdot%20%28%5Cfrac%7Bd%7D%7Bdx%7D%5Bx-y%5D%29)
Differentiate x like normally. Implicitly differentiate for y. This yields:

Distribute:

And that is our left side.
Right Side:
We have:
![\frac{d}{dx}[\frac{y}{8+x^2}]](https://tex.z-dn.net/?f=%5Cfrac%7Bd%7D%7Bdx%7D%5B%5Cfrac%7By%7D%7B8%2Bx%5E2%7D%5D)
We can use the quotient rule, where:
![\frac{d}{dx}[f/g]=\frac{f'g-fg'}{g^2}](https://tex.z-dn.net/?f=%5Cfrac%7Bd%7D%7Bdx%7D%5Bf%2Fg%5D%3D%5Cfrac%7Bf%27g-fg%27%7D%7Bg%5E2%7D)
f is y. g is (8+x²). So:
-(y)\frac{d}{dx}(8+x^2)}{(8+x^2)^2}](https://tex.z-dn.net/?f=%3D%5Cfrac%7B%5Cfrac%7Bd%7D%7Bdx%7D%5By%5D%288%2Bx%5E2%29-%28y%29%5Cfrac%7Bd%7D%7Bdx%7D%288%2Bx%5E2%29%7D%7B%288%2Bx%5E2%29%5E2%7D)
Differentiate:

And that is our right side.
So, our entire equation is:

To find dy/dx, we have to solve for y'. Let's multiply both sides by the denominator on the right. So:

The right side cancels. Let's distribute the left:

Now, let's move all the y'-terms to one side. Add our second term from our left equation to the right. So:

Move -2xy to the left. So:

Factor out a y' from the right:

Divide. Therefore, dy/dx is:

We can factor out a (8+x²) from the denominator. So:

And we're done!