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)

<- 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
+i , -j ... quadrant IV angle
2)

<-- i also got the magnitude of this one, but not the direction angle. again
-i , -j ... quadrant III angle
3)
what is your problem with this vector?
Find the vector v with the given magnitude and the same direction as u
v = < 1/sqrt(2) , -1/sqrt(2) >