grandes-ecoles 2016 QIII.B.2

grandes-ecoles · France · centrale-maths2__pc Proof Deduction or Consequence from Prior Results
We consider the family of polynomials $$\left\{ \begin{array}{l} H_0 = 1 \\ H_k = \frac{1}{k!} \prod_{j=0}^{k-1} (X - j) \quad \text{for } k \in \llbracket 1, n \rrbracket \end{array} \right.$$
Deduce a polynomial $P \in \mathbb{R}_5[X]$ such that $$\delta^2(P) = X^3 + 2X^2 + 5X + 7$$
We consider the family of polynomials
$$\left\{ \begin{array}{l} H_0 = 1 \\ H_k = \frac{1}{k!} \prod_{j=0}^{k-1} (X - j) \quad \text{for } k \in \llbracket 1, n \rrbracket \end{array} \right.$$

Deduce a polynomial $P \in \mathbb{R}_5[X]$ such that
$$\delta^2(P) = X^3 + 2X^2 + 5X + 7$$