Chapter 2 - Functions and Their Graphs - 2.2 The Graph of a Function - 2.2 Assess Your Understanding - Page 69: 53

$2\sqrt{10}$

The distance $d$ from $P_1(x_1,y_1)$ to $P_2(x_2,y_2)$ is given by the formula $d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$. Use the formula above to obtain: \begin{align*} d&=\sqrt{(1-3)^2+[0-(-6)]^2}\\ &=\sqrt{(-2)^2+6^2} \\&=\sqrt{4+36} \\&=\sqrt{40} \\&=\sqrt{4(10)}\\ &=2\sqrt{10} \end{align*}