Formulaic Maths Problems - get another problem: level 1, level 2, level 3 - link to this problem
Let $\mathbf{v} = \begin{pmatrix} -26.3 \\ 29.7 \\ -21.3 \end{pmatrix}$. Find $|\mathbf{v}|$.
Hint: Square the components, add the results together, then take the square root.
$\class{inputBox step1}{~\bbox[border:2px solid blue]{\strut\rlap{\class{inputReplace}{A1}}\hspace{54px}}~} {}^2 + \class{inputBox step1}{~\bbox[border:2px solid blue]{\strut\rlap{\class{inputReplace}{A2}}\hspace{54px}}~} {}^2 + \class{inputBox step1}{~\bbox[border:2px solid blue]{\strut\rlap{\class{inputReplace}{A3}}\hspace{54px}}~} {}^2$ $-26.3 {}^2 + 29.7 {}^2 + -21.3 {}^2$
$= \class{inputBox step2}{~\bbox[border:2px solid blue]{\strut\rlap{\class{inputReplace}{B1}}\hspace{54px}}~} + \class{inputBox step2}{~\bbox[border:2px solid blue]{\strut\rlap{\class{inputReplace}{B2}}\hspace{54px}}~} + \class{inputBox step2}{~\bbox[border:2px solid blue]{\strut\rlap{\class{inputReplace}{B3}}\hspace{54px}}~} = \class{inputBox step2}{~\bbox[border:2px solid blue]{\strut\rlap{\class{inputReplace}{BR}}\hspace{54px}}~}$ $= 691.69 + 882.09 + 453.69 = 2027.47$
Therefore,
$|\mathbf{v}| = \sqrt{\class{inputBox step3}{~\bbox[border:2px solid blue]{\strut\rlap{\class{inputReplace}{C1}}\hspace{54px}}~}} = \class{inputBox step3}{~\bbox[border:2px solid blue]{\strut\rlap{\class{inputReplace}{CR}}\hspace{54px}}~}$ $|\mathbf{v}| = \sqrt{2027.47} = 45.02743608$