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