Final answer:
The period of the function y = -3cos(x) is 2π, as the coefficient of x in the cosine function is 1 and does not alter the standard period of the cosine function.
Step-by-step explanation:
The period of a cosine function, such as y = -3cos(x), is determined by the coefficient of x inside the cosine function. Since there is no coefficient other than 1 (the function is cos(x), not cos(bx) where b is a different coefficient), the period is simply the standard period of the cosine function, which is 2π.
The cosine function completes one full cycle over a range of 2π radians, regardless of the amplitude (in this case, -3 does not affect the period). Therefore, the correct answer to the question 'Find the period of the function y = -3cos(x)' is option a) 2π.