Answer:
-4 is the answer to the product of two vectors.
Explanation:
We are given two vectors a and b such that:
a = 4i - 4j and b = 4i + 5j
Where i and j represent the unit vectors of x and y axis respectively with the property such that:
i.i= 1
i.j=0
j.i=0
j.j= 1
Now we are asked t find a.b
As a.b=(4i-4j)(4i+5j)
=4i×(4i)-4j×(4i)+4i×(5j)-4j×(5j)
=16i.i-16 i.j+20 i.j-20 j.j
= 16-0+0-20
= 16-20
= -4
Hence the value of a.b is -4.