Question

For \[\vec b_1=(1,2,2)\] and \[\vec b_2=(3,2,6)\], what is \[\vec b_1\cdot\vec b_2\]?

Options

• \[19\]

• \[9\]

• \[21\]

• \[49\]

Answer 1

The dot product is \[1\cdot3+2\cdot2+2\cdot6\]. Hence, \[\vec b_1\cdot\vec b_2=3+4+12=19\].