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यदि `A=[(1,2,3),(3,-2,1),(4,2,1)]` तो दर्शाइए कि `A^(3)-23A-40I=O` |
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Answer» `A^(2)=A.A=[(1,2,3),(3,-2,1),(4,2,1)][(1,2,3),(3,-2,1),(4,2,1)]` `=[(1+6+12,2-4+6,3+2+3),(3-6+4,6+4+2,9-2+1),(4+6+4,8-4+2,12+2+1)]` `=[(19,4,8),(1,12,8),(14,6,15)]` `A^(3)=A.A^(2)=[(1,2,3),(3,-2,1),(4,2,1)]=[(19,4,8),(1,12,8),(14,6,15)]` `=[(19+2+42,4+24+18,8+16+45),(57-2+14,12-24+6,24-16+15),(76+2+14,16+24+6,32+16+15)]` `=[(63,46,69),(69,-6,23),(92,46,63)]` `40I=40[(1,0,0),(0,1,0),(0,0,1)]=[(40,0,0),(0,40,0),(0,0,40)]` `:.A^(3)-23A-40I` `=[(63,46,69),(69,-6,23),(92,46,63)]-23[(1,2,3),(3,-2,1),(4,2,1)]-[(40,0,0),(0,40,0),(0,0,40)]` `[(63,46,69),(69,-6,23),(92,46,63)]+[(-23,-46,-69),(-69,46,-23),(-92,-46,-23)]` `+[(-40,0,0),(0,-40,0),(0,0,-40)]` `=[(63-23-40.46-46+0,69-69+0),(69-69+0,-6+46-40,23-23+0),(92-92+0,46-46+0,63-23-40)]` `=[(0,0,0),(0,0,0),(0,0,0)]=O` अत: `A^(3)-23A-40I=O` |
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