Final answer:
To find the cosine of angle 0, use the x-coordinate of the point on the terminal side of the angle.
Step-by-step explanation:
To find the cosine of angle 0, we can use the x-coordinate of the point (6, -8) on the terminal side of angle 0. The x-coordinate represents the adjacent side in the right triangle formed by the angle. So, cos 0 = adjacent/hypotenuse = 6/√(6^2 + (-8)^2) = 6/10 = 0.6.