Final answer:
In the unit circle, the value of tan(0) is 0, as it represents the ratio of the y-coordinate (opposite side) to the x-coordinate (adjacent side) at an angle of 0 degrees, which simplifies to 0.
Step-by-step explanation:
The value of the tangent function tan(θ) is defined on the unit circle as the ratio of the opposite side to the adjacent side in a right-angled triangle. For tan(0), since θ is 0 degrees, we look at the coordinates on the unit circle and find that the opposite side (which is the sine of the angle) is 0 and the adjacent side (which is the cosine of the angle) is 1. This yields a tan(0) value of 0/1, which simplifies to 0.