cari semua solusi(x,y) x²-xy-y²=5 2x²+2xy+y²=10
Matematika
primamugi123
Pertanyaan
cari semua solusi(x,y)
x²-xy-y²=5
2x²+2xy+y²=10
x²-xy-y²=5
2x²+2xy+y²=10
1 Jawaban
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1. Jawaban Takamori37
[tex]x^2-xy-y^2=5$ (kalikan 2)$ \\ $Menjadi,$ \\ 2x^2-2xy-2y^2=10 \\ 2x^2+2xy+y^2=10 \\ ---$Kurangi$--- \\ -4xy-3y^2=0 \\ 3y^2+4xy=0 \\ y(3y+4x)=0 \\ y_1=0,$ atau $3y_2=-4x \to y_2=-\frac{4}{3}x \\ $Untuk $y=0 \\ x^2-0-0=5 \\ x^2-5=0 \\ (x+\sqrt{5})(x-\sqrt{5})=0 \\ x=-\sqrt{5}$ dan $x=\sqrt{5}[/tex]
[tex]\\$Untuk $y=-\frac{4}{3}x \\ x^2+\frac{4}{3}x^2-\frac{16}{9}x^2=5 \\ \frac{5}{3}x^2=5 \\ x^2=3 \\ x^2-3=0 \\ (x+\sqrt{3})(x-\sqrt{3})=0 \\ x_1=-\sqrt{3}$ dan $x_2=\sqrt{3} \\ y_1=\frac{4}{3}\sqrt{3}$ dan $y_2=-\frac{4}{3}\sqrt{3} \\ \\ HP=\{(x,y)|(-\sqrt{5},0),(-\sqrt{3},\frac{4}{3}\sqrt{3}),(\sqrt{3},-\frac{4}{3}\sqrt{3}),(\sqrt{3},0)\}[/tex]