Solve the following determinant equations:


Let


We need to find the roots of Δ = 0.


Recall that the value of a determinant remains same if we apply the operation Ri Ri + kRj or Ci Ci + kCj.


Applying C1 C1 + C2, we get




Applying C1 C1 + C3, we get




Taking the term (3x – 2) common from C1, we get



Applying R2 R2 – R1, we get




Applying R3 R3 – R1, we get




Expanding the determinant along C1, we have


Δ = (3x – 2)(1)[(3x – 11)(3x – 11) – (0)(0)]


Δ = (3x – 2)(3x – 11)(3x – 11)


Δ = (3x – 2)(3x – 11)2


The given equation is Δ = 0.


(3x – 2)(3x – 11)2 = 0


Case – I:


3x – 2 = 0


3x = 2



Case – II:


(3x – 11)2 = 0


3x – 11 = 0


3x = 11



Thus, and are the roots of the given determinant equation.


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