Question

Find a ⋅ b. a = 4i - 4j, b = 4i + 5j

Answer 1

a=<4,-4>
b=<4,5>

a.b =4*4-4*5=16-20=-4

Answer 2

For this case we have the following vectors:

`a = 4i - 4j\\b = 4i + 5j`

We must find the product point of both vectors.

To do this, we multiply component by component and add the results.

We have then:

`a.b = (4) (4) + (-4) (5)\\a.b = 16 -20\\a.b = -4`

Answer:

The point product of both vectors is given by:

`a.b = -4`