11.2-bo'lim : Vektor arifmetikasi
1. Berilgan \(\vec a = \left\langle {8,5} \right\rangle \) va \(\vec b = \left\langle { - 3,6} \right\rangle \) quyidagilardan har birini hisoblang.- \(6\vec a\)
- \(7\vec b - 2\vec a\)
- \(\left\| {10\vec a + 3\vec b} \right\|\)
a \(6\vec a\) Yechim
Bu shunchaki skaler ko'paytirish muammosi. Faqat har bir komponentni skalerga ko'paytirishni unutmang, bu holda 6.
\[6\vec a = 6\left\langle {8,5} \right\rangle = \require{bbox} \bbox[2pt,border:1px solid black]{{\left\langle {48,30} \right\rangle }}\]b \(7\vec b - 2\vec a\) Yechim
Bu erda biz faqat har bir skalyar ko'paytirishni bajaramiz va keyin ayirishni bajaramiz. Ayirish bilan har bir vektordan mos keladigan komponentlarni ayirishni unutmang va esda tutingki, bu erda tartib muhim, chunki biz ayirish bilan shug'ullanamiz!
\[7\vec b - 2\vec a = 7\left\langle { - 3,6} \right\rangle - 2\left\langle {8,5} \right\rangle = \left\langle { - 21,42} \right\rangle - \left\langle {16,10} \right\rangle = \require{bbox} \bbox[2pt,border:1px solid black]{{\left\langle { - 37,32} \right\rangle }}\]c \(\left\| {10\vec a + 3\vec b} \right\|\) Yechim
Shunday qilib, avval biz kattalik chiziqlaridagi vektorni hisoblaymiz va kattalikni hisoblaymiz.
\[10\vec a + 3\vec b = 10\left\langle {8,5} \right\rangle + 3\left\langle { - 3,6} \right\rangle = \left\langle {80,50} \right\rangle + \left\langle { - 9,18} \right\rangle = \left\langle {71,68} \right\rangle \]Keyin kattalik,
\[\left\| {10\vec a + 3\vec b} \right\| = \sqrt {{{\left( {71} \right)}^2} + {{\left( {68} \right)}^2}} = \require{bbox} \bbox[2pt,border:1px solid black]{{\sqrt {9665} }}\]