As you travel on the unit circle counterclockwise from \(0\) radians to \(\frac {\pi }{2}\) radians, you move up and to the left.

On the interval \(\left (0, \frac {\pi }{2} \right )\), \(\cos (\theta )\) is increasing decreasing.

On the interval \(\left (0, \frac {\pi }{2} \right )\), \(-\sin (\theta )\) is positive negative.

As you travel on the unit circle counterclockwise from \(\frac {\pi }{2}\) radians to \(\pi \) radians, you move down and to the left.

On the interval \(\left (\frac {\pi }{2}, \pi \right )\), \(\cos (\theta )\) is increasing decreasing.

On the interval \(\left (\frac {\pi }{2}, \pi \right )\), \(-\sin (\theta )\) is positive negative.

As you travel on the unit circle counterclockwise from \(\pi \) radians to \(\frac {3\pi }{2}\) radians, you move down and to the right.

On the interval \(\left (\pi , \frac {3\pi }{2} \right )\), \(\cos (\theta )\) is increasing decreasing.

On the interval \(\left (\pi , \frac {3\pi }{2} \right )\), \(-\sin (\theta )\) is positive negative.

As you travel on the unit circle counterclockwise from \(\frac {3\pi }{2}\) radians to \(2\pi \) radians, you move up and to the right.

On the interval \(\left (\frac {3\pi }{2}, 2\pi \right )\), \(\cos (\theta )\) is increasing decreasing.

On the interval \(\left (\frac {3\pi }{2}, 2\pi \right )\), \(-\sin (\theta )\) is positive negative.