Question $25$

Given two vectors vec$(a)$ and vec$(b)$ where vec$(a)=\left[\begin{array}{c}{a}_x\\ a_y\\ a_z\end{array}\right]$ and vec$(b)=\left[\begin{array}{c}{b}_x\\ b_y\\ b_z\end{array}\right],$ what is vec$(a)*vec(b)?($Express your

answer WITHOUT using cosine$)$

Group of answer choices below

${\displaystyle \underset{1}{\overset{n}{}}}{a}_i{b}_i=a_x{b}_x+a_y{b}_y+a_z{b}_z$

$||vec(a)||||vec(b)||$

$||vec(a)||||vec(b)||cos$