Q. If $p\lambda^{4} + q\lambda^{3} + q\lambda^{2} + s\lambda + t = \left| \begin{matrix} b^{2} + c^{2} & a^{2} + \lambda & a^{2} + \lambda \\ b^{2} + \lambda & c^{2} + a^{2} & b^{2} + \lambda \\ c^{2} + \lambda & c^{2} + \lambda & a^{2} + b^{2} \end{matrix} \right|$ is an identity in $\lambda,$ where $p,q,r,s,t$ are constants, then the value of $t$ is

A) 1
B) 2
C) 0
D) None of these
Explanation

(d)
On putting $\lambda = 0$, we get
$t = \left| \begin{matrix}
b^{2} + c^{2} & a^{2} & a^{2} \\
b^{2} & {c^{2} + a}^{2} & b^{2} \\
c^{2} & c^{2} & a^{2} + b^{2}
\end{matrix} \right| = 4a^{2}b^{2}c^{2}$
Clearly, it depends on $a,b,c$.

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.

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