Here's the function

x^2 + 4y^2 - 2x - 16y + 13 = 0

Now time to take the derivative with respect to x, I got

fx = 2x + 0 - 2 - 0

= 2x - 2

Now time to take the derivative with respect to y, I got

fy = 0 + 8y - 0 - 16

= 8y - 16

This is what I got so far and Idk wether I did it right.... is there anything i did wrong?