Question

Problema 34. URGENT!!!

Answer 1

Răspuns:

OB=

$\sqrt{(xb - xo) {}^{2} + (yb - yo) {}^{2} }$

Explicație pas cu pas:

$\sqrt{9 + yb {}^{2} } = 3 \sqrt{5} \\ 9 + yb {}^{2} = 45 \\ yb {}^{2} = 36 \\ yb = + - 6$

Answer 2

$\it OB^2=(x_B-x_O)^2+(y_B-y_O)^2=(3-0)^2+(y-0)^2=9+y^2\ \ \ \ \ (1)\\ \\ OB=3\sqrt5 \Rightarrow OB^2=45\ \ \ \ \ \ (2)\\ \\ (1),\ (2) \Rightarrow 9+y^2=45|_{-9} \Rightarrow y^2=36 \Rightarrow y=\pm6$