Question

Point C has the coordinates (–1, 4) and point D has the coordinates (2, 0). What is the distance between points C and D?

Answer 1

$\bf \textit{distance between 2 points}\\ \quad \\ \begin{array}{lllll} &x_1&y_1&x_2&y_2\\ % (a,b) C&({{ -1}}\quad ,&{{ 4}})\quad % (c,d) D&({{ 2}}\quad ,&{{ 0}}) \end{array}\qquad % distance value d = \sqrt{({{ x_2}}-{{ x_1}})^2 + ({{ y_2}}-{{ y_1}})^2} \\\\\\ CD=\sqrt{[2-(-1)]^2+(0-4)^2}\implies CD=\sqrt{(2+1)^2+(-4)^2} \\\\\\ CD=\sqrt{9+16}\implies CD=\sqrt{25}\implies CD=5$

Answer 2

Use the distance formula: sqrt[(x1-x2)^2 - (y1-y2)^2]

x1: -1
x2: 2
y1: 4
y2: 0

Answer: 5