The expression you provided is $\cos(180^\circ)$.

To find the exact value of $\cos(180^\circ)$, we can refer to the unit circle. On the unit circle:

• $180^\circ$ corresponds to the point (-1, 0).
• The cosine of an angle is the x-coordinate of the corresponding point on the unit circle.

Thus, $\cos(180^\circ) = -1$.

The exact value of $\cos(180^\circ)$ is $-1$.

Would you like further details or have any other questions?

Here are some related questions you might find interesting:

1. What is the value of $\cos(90^\circ)$?
2. How do you calculate the sine of $180^\circ$?
3. What is the tangent of $180^\circ$?
4. Can you explain the unit circle and how it relates to trigonometric functions?
5. How do you calculate angles in radians instead of degrees?

Tip: The unit circle is a powerful tool to quickly find the values of sine, cosine, and tangent for key angles. It helps to visualize the trigonometric relationships.