Question

Tolong bantu ya. buat cara

Answer 1

X^2 + y^2 = 5
xy = 2 --> x = 2/y
substitusi

(2/y)^2 + y^2  = 5
4/y^2 + y^2 = 5
y^2 = a
4/a + a = 5
a^2 - 5a + 4 = 0
(a  -4)(a -1) = 0
a = 4 atau a = 1

untuk a= 4 --> y = 2 atau y = -2 
y = 2 --> x= 2/y = 1 --> A (1,2)
y = -2 --> x =2/y = -1 --> B( - 1, -2)

untuk a = 1 --> y = 1 atau y = -1
y = 1 --> x = 2 --> C(2,1)
y = -1 --> x = -2 --> D(-2, -1)

Jarak AC= √2
Jarak BC = 3√2
Luas persegi panjang ABCD  = AC x BC = 6