# What is the distance between  (–2, 0, 1)  and (–1, 4, –2) ?

${d}^{2} = {\left(- 2 - - 1\right)}^{2} + {\left(0 - 4\right)}^{2} + {\left(1 - - 2\right)}^{2}$ or
$d = \setminus \sqrt{1 + 16 + 9} = \sqrt{26}$