Signals and Systems Questions

1. Ideal filters are non causal, unstable and physically unrealized in the sense that characteristics can not be achieved with finite number of elements.
2. Transformation makes analysis of signal easier because certain features which may be obscure may be obvious in other form.
3. Correlation is a measure of similarity between two signals. Used in various application like radars
4. Linear convolution is a method of finding the response of a given system.
5.