Final answer:
Differentiation of the given inverse cosine function requires the use of the chain rule and an understanding of trigonometric identities and the Law of Cosines, more commonly studied at the college level.
Step-by-step explanation:
The solution to differentiate cos-1 {(a+bcosx)/(b+acosx)} involves applying the chain rule and the derivative of the inverse cosine function. The differentiation of the inverse trigonometric function is more advanced and often covered in college-level calculus courses. It would be essential to apply trigonometric identities such as cos(2θ) and the Law of Cosines to simplify the functions where applicable.