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If `A=[(1,2),(2,1)]` and `f(x)=(1+x)/(1-x)`, then f(A) isA. `[(1,1),(1,1)]`B. `[(2,2),(2,2)]`C. `[(-1,-1),(-1,-1)]`D. none of these |
Answer» Correct Answer - C `f(x)=(1+x)/(1-x)` or `(1-x) f(x)=1+x` `implies (I-A)f(A)=(I+A)` `implies f(A)=(I-A)^(-1)(I+A)` `=([(1,0),(0,1)]-[(1,2),(2,1)])^(-1) ([(1,0),(0,1)]+[(1,2),(2,1)])` `=([(0,-2),(-2,0)]^(-1)[(2,2),(2,2)])` `=([(0,2),(2,0)][(2,2),(2,2)])/(-4)` `=([(4,4),(4,4)])/(-4)` `=[(-1,-1),(-1,-1)]` |
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