Aspire's Library

A Place for Latest Exam wise Questions, Videos, Previous Year Papers,
Study Stuff for MCA Examinations - NIMCET

Previous Year Question (PYQs)



If $A = \begin{bmatrix} 3 & -2 \\ 4 & -2 \end{bmatrix}$ satisfies the matrix equation $A^2 - kA + 2I = 0$, then the value of $k$ is:






Solution

Trace of $A = 3 + (-2) = 1$

Determinant of $A = (3)(-2) - (-8) = -6 + 8 = 2$

Characteristic equation of $A$ is:

$\lambda^2 - (\text{trace})\lambda + \det = 0$

$\lambda^2 - \lambda + 2 = 0$

By Cayley–Hamilton theorem:

$A^2 - A + 2I = 0$

Comparing with $A^2 - kA + 2I = 0$

$k = 1$



Online Test Series,
Information About Examination,
Syllabus, Notification
and More.

Click Here to
View More


Online Test Series,
Information About Examination,
Syllabus, Notification
and More.

Click Here to
View More

Ask Your Question or Put Your Review.

loading...