WAEC - Further Mathematics (2015 - No. 21)
Given that \(r = 2i - j\), \(s = 3i + 5j\) and \(t = 6i - 2j\), find the magnitude of \(2r + s - t\).
\(\sqrt{15}\)
4
\(\sqrt{24}\)
\(\sqrt{26}\)
설명
\(r = 2i - j , s = 3i + 5j , t = 6i - 2j\)
\(2r + s - t = 2(2i - j) + (3i + 5j) - (6i - 2j) = i + 5j\)
\(|2r + s - t| = \sqrt{1^{2} + 5^{2}} = \sqrt{26}\)