The unit circle is a special circle that has a radius of 1. It is located in the center of a graph at the point (0,0). This circle is really useful for understanding sine and cosine, which are important in math. Here’s how it works:

• Coordinates: Every point on the unit circle can be linked to an angle, called $\theta$. For any point on the circle:

  • The $x$-coordinate (first number) is equal to $\cos(\theta)$.
  • The $y$-coordinate (second number) is equal to $\sin(\theta)$.

• Common Angles: There are some important angles we can use. These include:

  • $0^\circ$: This point is (1, 0).
  • $90^\circ$: This point is (0, 1).
  • $180^\circ$: This point is (-1, 0).
  • $270^\circ$: This point is (0, -1).

By knowing these angles and their points on the circle, we can easily find the sine and cosine values for each angle.