Question

Tolong berikan caranya terimakasih​

Answer 1

D. √17

Penjelasan dengan langkah-langkah:

Diketahui:

vektor [tex] \displaystyle\rm~\vec{a} [/tex] = 2i + 3j

vektor [tex] \displaystyle\rm~\vec{b} [/tex] = i - 2j

Ditanya:

[tex]\displaystyle\rm~ |\vec{a} + 2\vec{b}| = .... ?[/tex]

Penyelesaian:

[tex]\begin{aligned}\displaystyle\rm~ \vec{a} + 2\vec{b} & = \displaystyle\rm~ \binom{2}{3} + 2 \binom{1}{ - 2} \\ \\ & = \displaystyle\rm~ \binom{2}{3} + \binom{2}{ - 4} \\ \\ & = \displaystyle\rm~ \binom{2 + 2}{3 - 4} \\ \\ & = \displaystyle\rm~ \binom{4}{ - 1} \\ \end{aligned}[/tex]

maka,

[tex]\begin{aligned}\displaystyle\rm~ |\vec{a} + 2\vec{b}| & = \displaystyle\rm~ \sqrt{ {4}^{2} + {( - 1)}^{2} } \\ & = \displaystyle\rm~ \sqrt{16 + 1} \\ & = \displaystyle\rm~ \sqrt{17} \\ & \displaystyle\rm~\longmapsto~Opsi~D \end{aligned}[/tex]