Tolong berbagi ilmu pengetahuannya teman2... Mtk SMA XI

Lingkaran.
Kelompok peminatan kelas XI kurikulum 2013 revisi 2016.

Nomor 2
r = √[(x₁ - a)² + (y₁ - b)²]
  = √[(-12 - 0)² + (5 - 0)²] = 13 ← Jawaban: D

Nomor 3
3x + 4y + 7 = 0
p = 3, q = 4, s = 7; a = 3, b = 1
r = |pa + qb + s| / √(p² + q²)
  = |3(3) + 4(1) + 7| / √(3² + 4²) = 4

(x - a)² + (y - b)² = r²
(x - 3)² + (y - 1)² = 16
(x² - 6x + 9) + (y² - 2y + 1) - 16 = 0
x² + y² - 6x - 2y - 6 = 0
Jawaban: C.