# Trigonometry with Vectors

1. Oct 30, 2011

### C42711

[PLAIN]http://img832.imageshack.us/img832/449/physicsu.png [Broken]
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.:)

Last edited by a moderator: May 5, 2017
2. Oct 30, 2011

### Nytik

Tangent is not the correct function to use. 147km is the hypotenuse of the triangle.

3. Oct 30, 2011

### Millacol88

You'd need to use sine for the vertical and cosine for the horizontal. The sine of the angle is y / the hypotenuse, so y = sin71.2 * h. Similarly, x = cos71.2 * h. Hope that helps.

4. Oct 30, 2011

### C42711

So I tried that and got:
Fx= 47.4 km
Fy= 139 km

Does that seem correct?

5. Oct 30, 2011

### Nytik

Yeah, those are the correct values.

6. Oct 30, 2011

### C42711

Than you so much, you're the best.:)