Penjumlahan Vektor
Jika \(\textbf{u} = \left(\begin{array}{c}a\\ b\end{array}\right)\) dan \(\textbf{v} = \left(\begin{array}{c}c\\ d\end{array}\right)\) maka:
\(\textbf{u} + \textbf{v} = \left(\begin{array}{c}a\\ b\end{array}\right) + \left(\begin{array}{c}c\\ d\end{array}\right)\)
\(\textbf{u} +\textbf{v} = \left(\begin{array}{c}a + c\\ b + d\end{array}\right)\)
Pengurangan Vektor
Jika \(\textbf{u} = \left(\begin{array}{c}a\\ b\end{array}\right)\) dan \(\textbf{v} = \left(\begin{array}{c}c\\ d\end{array}\right)\) maka:
\(\textbf{u} \:-\: \textbf{v} = \left(\begin{array}{c}a\\ b\end{array}\right) \:-\: \left(\begin{array}{c}c\\ d\end{array}\right)\)
\(\textbf{u} \:-\: \textbf{v} = \left(\begin{array}{c}a \:-\: c\\ b \:-\: d\end{array}\right)\)
Contoh Soal
Soal 1 Jika \(\textbf{u} = \left(\begin{array}{c}-12\\ 5\end{array}\right)\) dan \(\textbf{v} = \left(\begin{array}{c}4\\ -3\end{array}\right)\), tentukan nilai \(\textbf{u} +\textbf{v} \)
\(\textbf{u} +\textbf{v} = \left(\begin{array}{c}-12\\ 5\end{array}\right) + \left(\begin{array}{c}4\\ -3\end{array}\right)\)
\(\textbf{u} +\textbf{v} = \left(\begin{array}{c}-12 + 4\\ 5 + (-3)\end{array}\right)\)
\(\textbf{u} +\textbf{v} = \left(\begin{array}{c}-8\\ 2\end{array}\right)\)
Soal 2
Jika \(\textbf{u} = \left(\begin{array}{c}12\\ 7\end{array}\right)\) dan \(\textbf{v} = \left(\begin{array}{c}4\\ 1\end{array}\right)\), tentukan \(||\textbf{u} \:-\:\textbf{v}||\)
\(\textbf{u} \:-\:\textbf{v} = \left(\begin{array}{c}12\\ 7\end{array}\right) \:-\: \left(\begin{array}{c}4\\ 1\end{array}\right)\)
\(\textbf{u} \:-\:\textbf{v} = \left(\begin{array}{c}12\:-\: 4\\ 7\:-\:1\end{array}\right)\)
\(\textbf{u} \:-\:\textbf{v} = \left(\begin{array}{c}8\\ 6\end{array}\right)\)
\(||\textbf{u} \:-\:\textbf{v}|| = \sqrt{8^2 + 6^2}\)
\(||\textbf{u} \:-\:\textbf{v}|| = \sqrt{64 + 36}\)
\(||\textbf{u} \:-\:\textbf{v}|| = \sqrt{100} = 10 \text{ satuan}\)
Soal 3
Tentukan nilai \(m\) yang memenuhi persamaan \(-2\left(\begin{array}{c}3\\ 1\end{array}\right) + \left(\begin{array}{c}-4\\ 2\end{array}\right) = \left(\begin{array}{c}1+m\\ 0\end{array}\right)\)
\(-2\left(\begin{array}{c}3\\ 1\end{array}\right) + \left(\begin{array}{c}-4\\ 2\end{array}\right) = \left(\begin{array}{c}1+m\\ 0\end{array}\right)\)
\(\left(\begin{array}{c}-6\\ -2\end{array}\right) + \left(\begin{array}{c}-4\\ 2\end{array}\right) = \left(\begin{array}{c}1+m\\ 0\end{array}\right)\)
\(\left(\begin{array}{c}-6 + (-4)\\ -2 + 2\end{array}\right) = \left(\begin{array}{c}1+m\\ 0\end{array}\right)\)
\(\left(\begin{array}{c}-10\\ 0\end{array}\right) = \left(\begin{array}{c}1+m\\ 0\end{array}\right)\)
\(-10 = 1 + m\)
\(-10\:-\:1 = m\)
\(m = -11\)