- #1

hardygirl989

- 21

- 0

## Homework Statement

Two vectors are given by A = 3i + j and = -1i + 2j.

A) Find A x B <---This is the cross product not multiplication.

B) Find the angle between A and B.

## Homework Equations

|AxB|=|A||B|sin(theta)

## The Attempt at a Solution

A) I used the determinant to find the cross product as 3(2)-1(-1)=7 <---This answer is correct

B) I need help with this problem...

I tried |AxB|=|A||B|sin(theta) to get θ= arcsin( |AxB| / ( |A||B| )

|A|=√(Ax^2+Ay^2)=3.16

|B|=√(Bx^2+Ay^2)=2.24

Thus, θ= arcsin(7/((3.16)(2.24)))=81.8 °.

However, it says that it is the wrong answer and I don't know why. Can anyone please help?

Thank you.