Answer
$\sqrt{x_{1^{2}}+m_{1^{2}}x_{1^{2}}}$
Work Step by Step
To find the distance between two points $(x_1,y_1)$ and ($x_2$,$y_2$), we use the distance formula:
$d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$
We find the distance from point $O(0,0)$ to $P(x_1,m_1x_1)$:
$d(O,\ P)=\sqrt{(x_{1}-0)^{2}+(m_{1}x_{1}-0)^{2}}$
$=\sqrt{x_{1^{2}}+m_{1^{2}}x_{1^{2}}}$
