Trigonometry with Vectors

[C42711]

By c42711 at 2011-10-30

I am supposed to find the X and Y components of the above vector. What I tried to do first was dot in a line, forming a triangle. I then tried to find the length of that line using tangent. I got 431.8, but I am not sure that is right. Next, I used the Pythagorean theorem to try to find the X and Y components, I got some crazy numbers, so I know I'm doing something wrong. Any help would be fantastic. Please & thank you.

 

[tkhunny]

You start with 147 and somehow end up with 431.8? That is a crazy number.

Have you considered dropping a perpendicular from the end of your vector and creating a right triangle with base onthe x-axis? Lable the x-component 'x' and the y-component 'y'. This should give:

\(\displaystyle \frac{x}{147} = \cos(71.2 deg)\)

\(\displaystyle \frac{y}{147} = \sin(71.2 deg)\)

And you should have

\(\displaystyle x^{2} + y^{2} = 147^{2}\)