Question

Find the angle between A=2i+2j-k and B=6i-3j+2k

Answer 1

Hi Mate!!!

There are two methods to solve this questions

one by using Dot products and the other by using Cross product.

We use Dot product as it is easier one.


à . B = A B Cos ( # )

Where # is angle between A and B

A.B = 12 -6 -2

A.B = 4 A = √(9). B =. √(49)

So,. 4 = 3 × 7 Cos(#)


4 / 21 = Cos (#)

# = Cos^-1 (4 /21)


Have a great future ahead

Answer 2

Let (theta) be angle between the vectors.
Cos(theta) =2(6)+2(-3)+(-1)2/v(4+4+1)*v(36+9+4)
=4/3*7
Cos(theta)=4/21
(theta)=cos(inverse) 4/21