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← JEE Main 2016 · 3 Apr · Shift 1
MathematicsSingle correct+4 / -1Question 65 of 90

JEE Main 2016 · 3 Apr · Shift 1, Mathematics question 65

The system of linear equations
x+λy−z=0x+\lambda y-z=0
λx−y−z=0\lambda x-y-z=0
x+y−λz=0x+y-\lambda z=0
has a non-trivial solution for :

Choose one option
Answer and worked solution

Official answer: D

Non-trivial solutions need
∣1λ−1λ−1−111−λ∣=λ3−λ=0,\begin{vmatrix}1&\lambda&-1\\\lambda&-1&-1\\1&1&-\lambda\end{vmatrix}=\lambda^3-\lambda=0,
so λ = 0, 1 or −1: exactly three values.