tolong kak, pake cara ya. saya bingung:(
Matematika
anonyymm
Pertanyaan
tolong kak, pake cara ya. saya bingung:(
1 Jawaban
-
1. Jawaban whongaliem
pusat lingkaran :
x - y - 1 = 0
x + y - 3 = 0
----------------- +
2x - 4 = 0
2x = 4
x = 4/2
x = 2
x + y - 3 = 0
2 + y - 3 = 0
y - 1 = 0
y = 1 ⇒ pusat ( 2,1)
jari jari lingkaran :
3x + 4y - 35 = 0 ⇒ k = 3 ; l = 4 ; m = - 35
r = | (a.k + b.l + m) / √(k² + l²) |
= | (2 . 3 + 1 .4 + - 35) / √(3² + 4²) |
= | (6 + 4 - 35) / √(9 + 16) |
= | (- 25) /√25
= 25/5
= 5
pers lingkaran :
(x - a)² + (y - b)² = r²
(x - 2)² + (y - 1)² = 5²
x² - 4x + 4 + y² - 2y + 1 = 25
x² + y² - 4x - 2y + 5 - 25 = 0
x² + y² - 4x - 2y - 20 = 0 ...... jawaban : A