Motion in 2 dimensions

Hi,

I have a Mechanics vector problem here split in two parts. First to solve the magnitude of the resultant vector and then to give the bearing at which it's acting at. Worked out most of it, but the last answer to the question isn't the same as mine. Kind of difficult to explain the question since I would need a diagram but hey, here it is:

Question:

A particle has velocity 4ms^-1 acting on it, in the east direction followed by a velocity of 5ms^1 acting at 30 degrees to the east direction.

I found the resultant vector to be of magnitude 8.7 ms^-1, But a bearing of 73.3 degrees???

The magnitude part is right however, they give a bearing of 20.5 degrees rather than 73.3.

For my bearing I done: 90 - tan^-1(5sin30/(4+5cos30)).

Any help? Thanks.

 

Atrocious grammar? How should it be corrected?

Also, I don't understand how the textbook can give a wrong value of bearing 20.5 degrees when you've ended up with an identical answer to me of 73.3 degrees.

I've checked my calculator skills, they seem pretty fine.

 

You know, you could've just replied with a simple correction to the question I asked on how to correct it. "I'm sorry" my grammar isn't the best, but at least you understand (I hope) what I'm saying, and right now, I'm completely confused.

Another option was to actually answer the real query I had about the textbook giving a bearing that was wrong to my solution. And that, I would've been grateful for.

 

lol. Thank you.

 

OK! woah! STOOPPP everyone!

CONCLUSION:

-I should've written: did not done
-The textbook has YET AGAIN given me a wrong answer.

Thanks everyone.