grandes-ecoles 2016 QIII.B.1

grandes-ecoles · France · centrale-maths2__pc Proof Computation of a Limit, Value, or Explicit Formula
We consider the family of polynomials $$\left\{ \begin{array}{l} H_0 = 1 \\ H_k = \frac{1}{k!} \prod_{j=0}^{k-1} (X - j) \quad \text{for } k \in \llbracket 1, n \rrbracket \end{array} \right.$$
Give the coordinates of the polynomial $X^3 + 2X^2 + 5X + 7$ in the basis $(H_0, H_1, H_2, H_3)$ of $\mathbb{R}_3[X]$.
We consider the family of polynomials
$$\left\{ \begin{array}{l} H_0 = 1 \\ H_k = \frac{1}{k!} \prod_{j=0}^{k-1} (X - j) \quad \text{for } k \in \llbracket 1, n \rrbracket \end{array} \right.$$

Give the coordinates of the polynomial $X^3 + 2X^2 + 5X + 7$ in the basis $(H_0, H_1, H_2, H_3)$ of $\mathbb{R}_3[X]$.