행렬식
Square Matrix 에 하나의 수를 대응
The term "determinant" existed before "matrix," and Joseph Sylvester named it "matrix" in the sense that it gives birth to a determinant.
Notation of determinant
detA,∣A∣2x2
acbd=ad−bc3x3
adgbehcfi=aei+bfg+cdh−ceg−bdi−afh