-
wilderness
- Master | Next Rank: 500 Posts
- Posts: 102
- Joined: Sat Mar 15, 2008 4:03 am
- Thanked: 4 times
I solved it and got the answer sqrt(3).
Here is what I did
1. Because of the quardinates of P, the angle formed by PO with negative x-axis must be -60. This is because tan of -60 is -sqrt(3).
2. Because the angle in the middle is 90, then the angle formed by QO with +ve x-axis is 30. (lets call this angle A)
3. Using the cordinates of P we can calculate its distance from O which gives us the radius of this semicircle. It turns out to be 2. (let call this X).
4. cos A = S / X
S = X cos A
= 2 cos 30
= 2 * { (sqrt 3) / 2)}
= sqrt 3
OA = 1 . HOW ??????
Here is what I did
1. Because of the quardinates of P, the angle formed by PO with negative x-axis must be -60. This is because tan of -60 is -sqrt(3).
2. Because the angle in the middle is 90, then the angle formed by QO with +ve x-axis is 30. (lets call this angle A)
3. Using the cordinates of P we can calculate its distance from O which gives us the radius of this semicircle. It turns out to be 2. (let call this X).
4. cos A = S / X
S = X cos A
= 2 cos 30
= 2 * { (sqrt 3) / 2)}
= sqrt 3
OA = 1 . HOW ??????
- Attachments
-
