Question

intr un sistem de coordonare xOy se considera pct A(3,4).Lungimea segmentului OA e de ...

Answer 1

$A(3,4);\quad O(0,0); \\ \\ |OA| = \sqrt{(x_A-x_O)^2+ (y_A-y_O)^2} = \sqrt{(0-3)^2+(0-4)^2} = \\ \\ = \sqrt{(-3)^2+(-4)^2} = \sqrt{9+16} = \sqrt{25} = 5$