Calculate the angles degree between the radius-vector of the point and the positive x-axis (measured counter-clockwise from the positive x-axis, within the limits of 180 degrees to positive 180 degrees)
^? what do i do? and how do i approach this problem?

x=-3.93
y=-3.18

2. Are you saying your teacher gave you this, but did not cover it during classes?

3. yea you could say that
i've never seen this before and i'm in pre-calculus!!

4. Originally Posted by gabriel
Calculate the angles degree between the radius-vector of the point and the positive x-axis (measured counter-clockwise from the positive x-axis, within the limits of 180 degrees to positive 180 degrees)
^? what do i do? and how do i approach this problem?

x=-3.93
y=-3.18
1. Draw a sketch.

2. Use the indicated right triangle to determine "the" angle. I didn't understand which angle was meant: The yellow one or the blue one?

5. For this you would use the Tangent rule.

$\mbox{angle} = tan^{-1}\left(\dfrac{\mbox{opposite length}}{\mbox{adjacent length}}\right)$

Substitute in the lengths, solve the angle to find the angle between the line and the closest x-axis. Then add the extra angles to find your total angle from the positive x-axis going counter-clockwise.

6. Well, keep it simple: just get angle opposite the side length 3.18, add 180.