Vector from angle and length

Hello, I need a little help again, I have been working on this for a couple hours, and I am stuck.

In my textbook I have this problem:

Find the vector that has a length of 5 and an angle of 220 with positive x axis on the form ai+bj

My best guess so far has been this:

(I have not been able to simplify this more)

and written it as this:

Now i controlled this by checking this:

But the answer provided in the back of the textbook is this:

My question is:

What am I doing wrong? I am completely stuck.

Re: Vector from angle and length

Quote:

Originally Posted by

**mariusg** In my textbook I have this problem:

Find the vector that has a length of 5 and an angle of 220 with positive x axis on the form ai+bj

My best guess so far has been this:

(I have not been able to simplify this more)

and written it as this:

Now i controlled this by checking this:

But the answer provided in the back of the textbook is this:

My question is:

What am I doing wrong? I am completely stuck.

You have done nothing wrong.

The answer goes with and not .