Algebra of Matrices — Maths STD 12 Science — Question
Gujarat BoardEnglish MediumSTD 12 ScienceMathsAlgebra of Matrices2 Marks
Question
For any square matrix write whether AAT is symmetric or skew-symmetric.
✓
Answer
$\big(\text{AA}^\text{T}\big)^\text{T}=\big(\text{A}^\text{T}\big)^\text{T}\times\text{A}^\text{T}$$\big\{\text{since, (AB)}^\text{T}=\text{B}^\text{T}\text{A}^\text{T}\big\}$ $\therefore\ \big(\text{AA}^\text{T}\big)^\text{T}=\big(\text{AA}^\text{T}\big)\ \dots(\text{i})$$\big\{\text{since, }(\text{A}^\text{T})^\text{T}=\text{A}\big\}$ We know that, a square matrix A is symmetric if AT = A So, from equation (i) (AAT) is a symmetric matric.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.