3 ms·
(sum_i ai x^i)(sum_j bj x^j) when you expand that, the coefficient of x^k is the sum of aibj such that i+j=k which is discrete convolution. Set x=10 and you'r
by sriku 6y ago
(sum_i ai x^i)(sum_j bj x^j) when you expand that, the coefficient of x^k is the sum of aibj such that i+j=k which is discrete convolution.
Set x=10 and you're dealing with decimal representation of numbers.
- rualca 6y ago> Set x=10 and (...) ...and you no longer have a function, only the image of a function at a specific point of its domain. Convolutions are functions, not functions evaluated at a specific, and cherry-picked point.