Question

Find a ⋅ b. a = 9i + 5j, b = 4i + 3j

Answer 1

ANSWER

$a.b = 51$


EXPLANATION


The given vectors are:


$a = 9i + 5j$
and

$b = 4i + 3j$


To find the dot product of the two vectors, we multiply the corresponding components and add them.


$a.b = 9 \times 4 + 5 \times 3$


This implies that,

$a.b = 36+ 15$


$a.b = 51$


Therefore the dot product of the two vectors is 51.

Answer 2

$\mathbf a\cdot\mathbf b=9\times4+5\times3=36+15=51$