tentukan titik pusat dan jari jari lingkaran berikut : a. x*+y*-12x-4y+36=0 b. x*+y*-4x-6y+5=0

a) x² + y² - 12x - 4y + 36 = 0
pusat (6, 2)
[tex] {r}^{2} = \frac{ {( - 12)}^{2} }{4} + \frac{ {( - 4)}^{2} } {4} - 36 \\ {r}^{2} = \frac{144}{4} + \frac{16}{4} - 36 \\ {r}^{2} = 36 + 4 - 36 \\ {r}^{2} = 4 \\ r = 2[/tex]

b) x² + y² - 4x - 6y + 5 = 0
pusat (2, 3)
[tex] {r}^{2} = \frac{ { - 4}^{2} }{4} + \frac{ { - 6}^{2} }{4} - 5 \\ {r}^{2} = \frac{16}{4} + \frac{36}{4} - 5 \\ {r}^{2} = 4 + 9 - 5 \\ {r }^{2} = 8 \\ r = \sqrt{8} [/tex]