Nth Derivative of xⁿyⁿ by Leibniz Theorem | Solved Example - Math Traders

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Nth Derivative of xⁿyⁿ by Leibniz Theorem | Solved Example

Nth Derivative of xnyn Using Leibniz Theorem

In this problem, we evaluate the nth derivative of xnyn using the Leibniz Theorem. This method is commonly applied to higher-order derivatives involving products of functions.


Problem

Find the nth derivative of y = xn · yn using Leibniz theorem.

Solution

Leibniz Theorem

dn/dxn(uv) = Σ C(n, r) · dru/dxr · dn−rv/dxn−r,
where r = 0 to n

Step 1: Choose Functions

u = xn
v = yn

Step 2: Derivatives of Each Function

Derivative of u = xn:

dr/dxr(xn) = n(n−1)(n−2)…(n−r+1)xn−r

Derivative of v = yn:

dn−r/dxn−r(yn) = n(n−1)(n−2)…(r+1)yr

Step 3: Apply Leibniz Theorem

dn/dxn(xnyn) = Σ C(n, r) · [n(n−1)…(n−r+1)xn−r] · [n(n−1)…(r+1)yr]

This is the required general expression.