Question

Find the distance between the points $P(1, -3, 4)$ and $Q (-4,1,2)$.

• A. $\sqrt{5}$ units
• B. $5\sqrt{3}$ units
• C. $3\sqrt{5}$ units
• D. $2\sqrt{2}$ units

Answer 1

Answer: (C)

$3\sqrt{5}$ units

Answer 2

The distance between the points $P(1, -3, 4)$ and $Q(-4,1,2)$ is $PQ = \sqrt{\left(-4-1\right)^{2}+\left(1+3\right)^{2}+\left(2-4\right)^{2}}$ $= \sqrt{25+16+4}= \sqrt{45}$ $= 3\sqrt{5}$ units