3 and 4 .Determinants and Matrices
easy

શ્રેણિક $A = \frac{1}{3}\left[ {\begin{array}{*{20}{c}}1&2&2\\2&1&{ - 2}\\{ - 2}&2&{ - 1}\end{array}} \right]$ એ. . .

A

Orthogonal

B

Involutory

C

Idempotent

D

Nilpotent

Solution

(a) Since for given $A = \frac{1}{3}\left[ {\begin{array}{*{20}{c}}1&2&2\\2&1&{ – 2}\\{ – 2}&2&{ – 1}\end{array}\,} \right]$ $A{A^T} = {A^T}A = {I_{(3 \times 3)}}$. Thus $A $ is orthogonal.

Standard 12
Mathematics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.