x2+y2+−2x−6y+5=0
When differentiated:
x2+y2+−2x−6y+5=0 → 2x + 2y - 2 - 6 = 0
where x=3 and y=2
2[3] + 2[2] - 8 = 0
6 + 4 - 8 = 2