Bourbaki

Exercise 6, § 2

Functions of a Real Variable, IV, 205

Let f(X)f(X) be a polynomial of degree nn with complex coefficients, and let

1f(X)=∑j=1q∑h=1njλjh(X−rj)h \frac{1}{f(X)} = \sum_{j=1}^{q} \sum_{h=1}^{n_j} \frac{\lambda_{jh}}{(X - r_j)^h}

be the decomposition of the rational fraction 1/f(X)1/f(X) into simple elements (Alg., VII. 7, n 2). Show that, for any regulated function bb, the function

t↦∑j=1q∑h=1njλjh∫t0t(t−s)h−1(h−1)!elj(t−s)b(s)ds t \mapsto \sum_{j=1}^{q} \sum_{h=1}^{n_j} \lambda_{jh} \int_{t_0}^{t} \frac{(t-s)^{h-1}}{(h-1)!} e^{l_j(t-s)} b(s) ds

is an integral of the equation f(D)x=b(t)f(D)x = b(t).

Solution

No solution has been written yet.

Transcribed from the printed volume. Not translated.