# Homework Help: Vectors and finding components

1. Sep 30, 2010

### joej24

1. The problem statement, all variables and given/known data
If the x component of a vector A, in the xy plane, is half as large as the magnitude of the vector, the tangent of the angle between the vector and the x axis is:
B 1/2
D 3/2
E 3

2. Relevant equations

3. The attempt at a solution
I first drew a right triangle and realized that the description fit a 30 - 60 - 90 triangle. Is it wrong to assume that the vector and its components make a right triangle?

So I assumed that the magitude of the vector was 2x, the x component x, and the y component (rad 3) x. The tangent of the angle between the angle and x axis I would then be (rad3)x / x = rad3.
Is this correct? According to my answer sheet, the answer is D (3/2). I dont think the solution sheet is correct

2. Sep 30, 2010

### betel

Y and X axis make a right angle in any reasonable coordinate system. So vector, x and y-axis will make a right triangle.
If rad means square root, then $$\sqrt{3}$$ is the correct answer.

3. Oct 1, 2010

### joej24

Thanks! I think the answer sheet was wrong. And by rad 3 I did mean square root 3.