My question is from Matrices grade 12 ... no links pls:

​Let  A = 0 1 - 1 0 ,   Find   x   and   y   such   that   xI   +   y A 2 = A .

Dear student
Given: A=01-10Consider,xI+yA2=Ax1001+y01-102=01-10x00x+0y-y02=01-10xy-yx2=01-10xy-yxxy-yx=01-10x2-y2xy+xy-xy-xy-y2+x2=01-10x2-y22xy-2xyx2-y2=01-10On comparing , we getx2-y2=0 and 2xy=1x2=y2 and xy=12x=12y12y2=y214y2=y24y4=1y4=14On solving we gety=±12,±i12   Case I, When y=12So, x=12×12=12Case II, When y=-12So, x=12×-12=-12

Case III: When y=i2then , x=12×i2=22i=12i×ii=i-2  as i2=-1Case IV: When y=-i2then , x=12×-i2=-22i=-12i×ii=-i-2=i2  as i2=-1
Regards

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