Tentukan persamaan garis singgung lingkaran x2+y2-10x+6y-66=0 dengan gradien m=4/3

x²+y²-10x+6y-66=0
A=-10 B=6 C=-66
O(a,b) = (-1/2A, -1/2B) = (5,-3)
r = √a²+b²-C = √25+9-(-66) = √100 = 10
m = 4/3

y-b = m(x-a) ± r√m²+1
y+3 = 4/3(x-5) ± 10√(4/3)²+1
y+3 = 4/3x - 20/3 ± 10√25/9
y+3 = 4/3x - 20/3 ± 50/3

>>> 1. y = 4/3x + 7 atau 4/3x - y + 7 = 0
>>> 2. y = 4/3x - 79/3 atau 4/3x-y-79/3 = 0