mathematical tip

标签（空格分隔）： mathematics

1.addition time difference
2.transformation

\((a+b)\times(a+(-b))=a^2-b^2\)

->

c : coefficients
\((a+c\times b)\times(a-c\times b)=a^2-c^2b^2\)

->

\((c_1\times a +c_2\times b)\times(c_1\times a-c_2\times b)=c_1^2a^2-c_2^2b^2\)

6row1 + 3row1 :

3row1 -> 3(row1+2row2)

row1 + 2row2 -> 3(row1+2row2)

Given a square matrix A ,which acts on a identiy matrix I then producing A.if we undo what A acts on I which is to obtain A\(^{-1}\).inverse matrix