To solve for csc^-1(cotanΘ) given that tan^-1(3/5) = Θ, one can express everything in terms of sine and cosine or draw a right triangle with legs of 3 and 4. Using the Pythagorean theorem, the hypotenuse can be calculated, allowing for the determination of cotan(Θ). The relationship simplifies to csc^-1(cot(Θ)) = csc^-1(1/tan(Θ)), which further resolves to csc^-1(5/3). This method provides a clear path to the solution.