8cos

8cos refers to a specific trigonometric value, the cosine of 8 radians. Radians are a unit of angular measurement, where one radian is the angle subtended at the center of a circle by an arc equal in length to the radius. A full circle is 2π radians, which is approximately 6.283 radians. Therefore, 8 radians is an angle that has completed one full rotation and continued further.

The cosine function is a fundamental trigonometric function that relates an angle of a right-angled triangle to the ratio of the length of the adjacent side to the length of the hypotenuse. In the context of the unit circle, the cosine of an angle is the x-coordinate of the point where the terminal side of the angle intersects the circle. The value of cos(8) is a specific real number.

To determine the approximate value of cos(8), one would typically use a calculator or trigonometric tables. Since 8 radians is greater than 2π, it represents an angle that has gone past a full circle. Specifically, 8 radians is approximately 8 - 2π radians, which is about 1.717 radians. This angle lies in the second quadrant of the unit circle, where the cosine function is negative. The approximate value of cos(8) is -0.1455. This value is irrational, meaning it cannot be expressed as a simple fraction.