If the vectors $\mathrm{AB}=-3 \mathbf{i}+4 \mathbf{k}$ and $\mathrm{AC}=5 \mathbf{i}-2 \mathbf{j}+4…
- $\sqrt{14}$
- $\sqrt{18}$
- $\sqrt{25}$
- $\sqrt{29}$
Solution

$\begin{aligned} & =\frac{1(-3 \mathbf{i}+4 \mathbf{k})+1(5 \mathbf{i}-2 \mathbf{j}+4 \mathbf{k})}{1+1} \\ & =\mathbf{i}-\mathbf{j}+4 \mathbf{k} \\ & \therefore|\mathrm{AD}|=\sqrt{1+1+16}=\sqrt{18}\end{aligned}$
Asked in: AP EAMCET 2011