Question

B) x² + y² - 2(x +2y) + 5 ≥ 0.​

Answer 1

Объяснение:

B)

$x^2+y^2-2*(x+2y)+5\geq 0\\\\x^2+y^2-2x-4y+4+1\geq 0\\\\(x^2-2x+1)+(y^2-4y+4)\geq 0\\\\(x-1)^2+(y-2)^2\geq 0\ \ \ \ \ \ \Rightarrow\\\\\displaystyle\left \{ {{(x-1)^2\geq 0} \atop {(y-2)^2\geq 0}} \right. \ \ \ \ \ \ \Rightarrow\ \ \ \ \ \ \left \{ {{x\in(-\infty;+\infty)} \atop {y\in(-\infty;+\infty)}} \right. .$