I just started on vector and there are some confusing problems i want to ask:

Find the magnitude and direction angle of the vector:

1)\(\displaystyle 3i-4j\)<- on this one i found the magnitude but not the direction angle, though i'm positive that i did just like i've done with some previous problems. I got 53.13, but the answer in the book is 306.87

2)\(\displaystyle -3i-5j\)<-- i also got the magnitude of this one, but not the direction angle. again

3)\(\displaystyle 7(cos135i+sin135j)\)

Find the vector v with the given magnitude and the same direction as u

\(\displaystyle |v| = 1, u =<3,-3>\)

Please help! Thanks(Happy)

Find the magnitude and direction angle of the vector:

1)\(\displaystyle 3i-4j\)<- on this one i found the magnitude but not the direction angle, though i'm positive that i did just like i've done with some previous problems. I got 53.13, but the answer in the book is 306.87

2)\(\displaystyle -3i-5j\)<-- i also got the magnitude of this one, but not the direction angle. again

3)\(\displaystyle 7(cos135i+sin135j)\)

Find the vector v with the given magnitude and the same direction as u

\(\displaystyle |v| = 1, u =<3,-3>\)

Please help! Thanks(Happy)

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