Question

Two vectors are given as A⃗ = 2i^ + 3j^ − 3k^ and B⃗ = -1i^ + 5j^ + 3k^. Find A⃗ ⋅ B⃗

Answer 1

A·B = 4

Step-by-step explanation:

Given that,

Vector A = 2i+3j-3k

Vector B = -i+5j+3k

We need to find the value of A·B.

We know that,

i·i=j·j=k·k = 1 and i·j=j·k=k·i=0

So,

`A\cdot B=(2i+3j-3k)\cdot (-i+5j+3k)\\\\=-2+5(3)+(-3)(3)\\\\=-3+15-9\\\\=4`

So, the value of A·B is equal to 4.