Answer: The value of cos(0) is 1. This is because when the angle is 0 degrees, the adjacent side of the right triangle is equal to the hypotenuse, and the cosine of 0 is the ratio of the adjacent side to the hypotenuse. Therefore, cos(0) = 1.

Explanation: First, we need to understand some basic concepts about trigonometry. Trigonometry is the branch of mathematics that deals with the relationships between the sides and angles of triangles. In particular, the trigonometric functions sine, cosine, and tangent are used to describe these relationships.

The cosine function is defined as the ratio of the adjacent side to the hypotenuse of a right triangle. In other words, if we have a right triangle with one angle measuring θ, and the adjacent side to that angle is a, and the hypotenuse is h, then cos(θ) = a/h.

Now, let's consider the special case where θ = 0. In this case, the adjacent side to the angle is 0 (since there is no angle to the right of the hypotenuse), and the hypotenuse is simply the length of the hypotenuse. Therefore, cos(0) = 0/h = 0.

So, in conclusion, the value of cos(0) is 0. This makes sense, since when θ = 0, the adjacent side of the triangle is 0, meaning there is no horizontal displacement from the origin, which corresponds to cos(0) = 0. This is also reflected on the unit circle, where the x-coordinate of the point where the angle intersects the circle is 1, which corresponds to cos(0) = 1.