Mathematics for IGCSE & O level - Vectors (Section 2 - No. 12)
If \(\vec{a} = \begin{pmatrix} 1 \\ 1 \end{pmatrix}\), what is the magnitude of 2\(\vec{a}\)?
2
\(2\sqrt{2}\)
4
\(\sqrt{2}\)
Giải thích
2\vec{a} = \begin{pmatrix} 2 \\ 2 \end{pmatrix}\). The magnitude is \(\sqrt{2^2 + 2^2} = \sqrt{8} = 2\sqrt{2}\).