Definition
A linear system is one that satisfies both superposition and homogeneity. Superposition means that the system passes the following test: $ f(x+y)=f(x)+f(y) $. Homogeneity means that system passes the following test: $ f(ax)=af(x) $.
A linear system is one that satisfies both superposition and homogeneity. Superposition means that the system passes the following test: $ f(x+y)=f(x)+f(y) $. Homogeneity means that system passes the following test: $ f(ax)=af(x) $.