Question

Aflati distanta dintre punctele A (3,-1); B (-1,12)​

Answer 1

$\it AB^2=(x_B-x_A)^2+(y_B-y_A)^2 =(-1-3)^2+(12+1)^2=(-4)^2+13^2=\\ \\ =16+169=$

Answer 2

$\it d_{AB}  = \sqrt{(x_{B} - x_{A})^{2} + (y_{B} - y_{A})^{2} } = \sqrt{(-1 - 3)^{2} + (12 + 1)^{2}} =  \sqrt{(-4)^{2} + 13^{2} }  = \\ = \sqrt{185}$