Precalc vector problem, please help? Picture associated with problem will be attached.

The question is: Find the magnitude and direction of the resultant vector for the diagram.

The first part I did, and I think it's right.

(15.4,42.3)+(73.7,51.6)
=(89.1,93.9)
sqrt(89.1^2+93.9^2)
=sqrt(793.81+8817.21)
=about 129.5

Answer choices:
A. 129.5N, 46.5 degrees
B. 129.5N, 11.5 degrees
C. 113.6N, 13.1 degrees
D. 113.6N, 48.1 degrees

So I think the answer is either A or B, but I don't know how to find the direction of the resultant vector... Help?

Question

Precalc vector problem, please help? Picture associated with problem will be attached.

The question is: Find the magnitude and direction of the resultant vector for the diagram.

The first part I did, and I think it's right.

(15.4,42.3)+(73.7,51.6)
=(89.1,93.9)
sqrt(89.1^2+93.9^2)
=sqrt(793.81+8817.21)
=about 129.5

Answer choices:
A. 129.5N, 46.5 degrees
B. 129.5N, 11.5 degrees
C. 113.6N, 13.1 degrees
D. 113.6N, 48.1 degrees

So I think the answer is either A or B, but I don't know how to find the direction of the resultant vector... Help?

anonymous · Answer

attachment

johnweldon1993 · Answer

Oh the direction? You would do the inverse tan function on y/x

$$\theta = \tan^{-1} \frac{93.9}{89.1}$$

anonymous · Answer

Oh, that's all? Hmmm simpler than I thought it was haha :) thanks!

johnweldon1993 · Answer

No problem :)