Question

Find the dot product between the vectors u and v: u=2i+3j and v=-6i-5j

Answer 1

$\bf \stackrel{\textit{dot product}}{\cdot }\implies (a\cdot c)+(b\cdot d) \\\\[-0.35em] ~\dotfill\\\\ \begin{cases} u=&2i+3j\\ v=&-6i-5j \end{cases}\implies \begin{cases} \\ \end{cases} \\\\\\ \cdot \implies (2\cdot -6)+(3\cdot -5)\implies -27$