Question

if a is a singular,then inverse of lambda =?​

Answer 1

Answer:

∣A∣=0 as the matrix A is singular.

∴∣A∣=

∣

∣

∣

∣

∣

∣

∣

∣ 1

2

3

3

4

5

λ+2

8

10

∣

∣

∣

∣

∣

∣

∣

∣

∣

=0

Apply R

2

2

2 →R

2

2

2 −2R

1

1

1 and R

3

3

→R

3

−3R

1

1

1 and expand.

−2(4−λ)+4(4−2λ)=0

⇒8−2λ=0

⇒λ=4

For λ=4, the second and the third column are proportional.

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