How would you write this in Sigma notation

Question

I stumbled upon this expression:$$p_nq_mx^{m+n}+(p_{n-1}q_m+p_nq_{m-1})x^{m+n-1}+(p_{n-2}q_m+p_{n-1}q_{m-1}+p_nq_{m-2})x^{m+n-2}+\ldots+p_0q_0\tag1$$ And I'm wondering if there is an easier way to represent $(1)$ using the sum notation Sigma: $\sum$.

Are you sure the last term $p_0q_0$ is correct? It doesn't seem to match up with the rest. — Alex R., Jan 20 '17 at 23:08
That would be the $x^m$ term which is somewhere in the middle. — Dan Rust, Jan 20 '17 at 23:11

score 4 · Accepted Answer · answered Jan 20 '17 at 23:07

4

$$\sum_{i=0}^{n}\sum_{j=0}^{m} p_iq_jx^{i+j}$$

answered Jan 20 '17 at 23:07

Dan Rust

30,108

Cool, good enough! Thanks! – Crescendo Jan 20 '17 at 23:07

How would you write this in Sigma notation

1 Answers1