Chắc đề là tính đạo hàm của \(y=cot^3\left(\dfrac{3\pi x}{2}\right)\)?
Nếu vậy:
\(y'=3cot^2\left(\dfrac{3\pi x}{2}\right).\left[cot\left(\dfrac{3\pi x}{2}\right)\right]'=3cot^2\left(\dfrac{3\pi x}{2}\right).\left(-\dfrac{1}{sin^2\left(\dfrac{3\pi x}{2}\right)}\right).\dfrac{3\pi}{2}\)
\(=-\dfrac{9\pi}{2}.\dfrac{cos^2\left(\dfrac{3\pi x}{2}\right)}{sin^4\left(\dfrac{3\pi x}{2}\right)}\)