Of the flowing four cosine values (radians) which is the greatest A.cos 7.28 B.cos 8.28 C.cos 6.28 D.cos 5.28?

To determine which cosine value is the greatest, we can evaluate each angle. The cosine function decreases in value as the angle increases from 0 to π (approximately 3.14 radians) and then starts increasing again towards 2π (approximately 6.28 radians). Among the options provided, cos 6.28 (which is approximately cos(0) = 1) is the highest, making it the greatest cosine value of the four. Thus, the greatest value is C. cos 6.28.