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For which value(s) of λ , do the pair of linear equationsλx + y = λ2 and x + λy = 1 have(i) no solution?(ii) infinitely many solutions?(iii) a unique solution? |
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Answer» The given pair of linear equations is λx + y = λ2 and x + λy = 1 a1 = λ, b1= 1, c1 = – λ2 a2 =1, b2=λ, c2=-1 The given equations are; λ x + y – λ2 = 0 x + λ y – 1 = 0 Comparing the above equations with ax + by + c = 0; We get, a1 = λ, b1 = 1, c1 = – λ 2; a2 = 1, b2 = λ, c2 = – 1; a1 /a2 = λ/1 b1 /b2 = 1/λ c1 /c2 = λ2 (i) For no solution, a1/a2 = b1/b2≠ c1/c2 i.e. λ = 1/ λ ≠ λ2 so, λ 2 = 1; and λ 2 ≠ λ Here, we take only λ = – 1, Since the system of linear equations has infinitely many solutions at λ = 1, (ii) For infinitely many solutions, a1/a2 = b1/b2 = c1/c2 i.e. λ = 1/ λ = λ2 so λ = 1/ λ gives λ = + 1; λ = λ 2 gives λ = 1,0; Hence satisfying both the equations λ = 1 is the answer. (iii) For a unique solution, a1/a2 ≠ b1/b2 so λ ≠1/ λ hence, λ2 ≠ 1; λ ≠ + 1; So, all real values of λ except +1 |
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