salah satu persamaan garis singgung pada lingkaran x²+ y²- 2x- 4y - 14 = 0. yang tegak lurus garis x + 2y- 3 = 0 adalah....

x² + y² - 2x - 4y - 14 = 0
A = -2, B = -4 dan C = -14
pusat= (-(1/2)A, -(1/2)B) = (1, 2)
r = √(1² + 2² - C) = √(1 + 4 + 14) = √19
x + 2y - 3 = 0 → 2y = -x + 3 → y = -(1/2)x + 3/2
m = -1/2
tgk lurus → m1 = -1/m = -1/(-1/2) = 2
y - b = m1(x - a) ± r√(1  + m1²)
y - 2 = 2(x - 1) ± √19√(1 + 2²)
y = 2x ± √95
PGS
y = 2x + √95, atau
y = 2x - √95