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If `A=[-1 1 0-2]`, then prove that `A^2+3A+2I=Odot`Hence, find `Ba n dC`matrices of order 2 with integer elements, if `A=B^3+C^3dot` |
Answer» `A=[(-1,1),(0,-2)]` `implies A^(2)=[(-1,1),(0,-2)][(-1,1),(0,-2)]=[(1,-3),(0,4)]` `implies A^(2)+3A+2I` `=[(1,-3),(0,4)]+3[(-1,1),(0,-2)]+2[(1,0),(0,1)]=[(0,0),(0,0)]` `implies A^(2)+3A+2I =O` (1) From (1), `A^(3)+3A^(2)+2A=O` `implies (A+I)^(3)-A=I^(3)` `implies A=(A+I)^(3)-I^(3)=(A+I)^(3)+(-I)^(3)` `implies B=A+I` and `C=-I` `:. B=[(-1,1),(0,-2)]+[(1,0),(0,1)]=[(0,1),(0,-1)]` and `C=[(-1,0),(0,-1)]` |
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