Which of the following statements about the sine function is correct?

• A. It has a period of 360 degrees or 2π radians and sin 0 = 0
• B. It has a period of 90 degrees
• C. It has a vertical asymptote at x = 0
• D. It is defined only for positive x

Answer: (A)

Think about how the sine wave behaves: it repeats its pattern every full cycle, so its period is 2π radians (360 degrees). At x = 0, sin 0 equals 0, which is the starting point of the wave. The sine function is defined for all real numbers and stays between -1 and 1, with no vertical asymptotes. It also accepts negative x values, since sin(-x) = -sin(x). So the statement that the period is 360 degrees (or 2π radians) and sin 0 = 0 is the correct one.