Question

I’d like the distance between the origin and a point

Answer 1

The distance between points (x1, y1) and (x2, y2) can be calculated as follows:

$d=\sqrt[]{(x_2-x_1)^2+(y_2-y_1)^2}$

If one of the points is the origin, say (x1, y1) = (0, 0), then:

$\begin{gathered} d=\sqrt[]{(x_2-0)^2+(y_2-0)^2} \\ \text{Operate:} \\ d=\sqrt[]{x_2^2+y_2^2} \end{gathered}$

We only need the coordinates of one of the points and use the formula above, thus the correct choice is B.