⎡⎢⎣cosα−sinα0sinαcosα0001⎤⎥⎦=⎡⎢⎣100010001⎤⎥⎦A
R1→R1cosαR2→R2sinα
⎡⎢⎣cos2α−cosαsinα0sin2αcosαsinα0001⎤⎥⎦=⎡⎢⎣cosα000sinα0001⎤⎥⎦A
R1→R1+R2
⎡⎢⎣cos2α+sin2α−cosαsinα+cosαsinα0sin2αcosαsinα0001⎤⎥⎦=⎡⎢⎣cosαsinα00sinα0001⎤⎥⎦A
⎡⎢⎣100sin2αcosαsinα0001⎤⎥⎦=⎡⎢⎣cosαsinα00sinα0001⎤⎥⎦A
R2→R2−R1sin2α
⎡⎢⎣100sin2α−sin2αcosαsinα0001⎤⎥⎦=⎡⎢⎣cosαsinα0−cosαsin2αsinα−sin3α0001⎤⎥⎦A
⎡⎢⎣1000cosαsinα0001⎤⎥⎦=⎡⎢⎣cosαsinα0−cosαsin2αsinαcos2α0001⎤⎥⎦A
R2→R2cosαsinα
⎡⎢⎣100010001⎤⎥⎦=⎡⎢⎣cosαsinα0−sinαcosα0001⎤⎥⎦A
A−1=⎡⎢⎣cosαsinα0−sinαcosα0001⎤⎥⎦