Point P is the intersection of the terminal arm of angle in standard position and th

1. Apr 15, 2009

FalconF1

1. The problem statement, all variables and given/known data
Point P is the intersection of the terminal arm of angle (-) in standard position and the unit circle with centre (0, 0). If P is in quadrant 2 and sin (-)= m, determine the coordinates of P in terms of m.

2. Relevant equations

3. The attempt at a solution
no idea

2. Apr 16, 2009

psycho2499

Re: Point P is the intersection of the terminal arm of angle in standard position an

This is a lovely example of the special properties of the unit circle. The first thing you should do though with a problem like this is draw a picture.

http://img24.imageshack.us/my.php?image=tempw.jpg

3. Apr 16, 2009

psycho2499

4. Apr 16, 2009

yeongil

Re: Point P is the intersection of the terminal arm of angle in standard position an

FalconF1, what is the definition of $$sin \theta$$ and $$cos \theta$$ in a unit circle?

01

5. Apr 16, 2009

psycho2499

Re: Point P is the intersection of the terminal arm of angle in standard position an

The definition of sin theta in any case is opposite/hypotenuse and cos theta is adjecent/hypotenuse. The unit circle has a radius of 1 so any right triangle with vertices at the origin, a point P on the circle, and the X or Y axis ( is a purely your choice, most choose the X axis ) will have a hypotenuse of 1. So if you chose to drop to the X axis then sin theta = Y/1 and cos theta = X/1.

6. Apr 16, 2009

psycho2499

Re: Point P is the intersection of the terminal arm of angle in standard position an

My teacher used to say that the easiest way to remember sin theta is Y sin

Last edited: Apr 16, 2009