Given that A = [8(α β γ -α )] and A 2 = 3I, then :
(a) 1 + ๐ผ 2 + ๐ฝ๐พ = 0 (b) 1 − ๐ผ 2 − ๐ฝ๐พ = 0
(c) 3 − ๐ผ 2 − ๐ฝ๐พ = 0 (d) 3 + ๐ผ 2 + ๐ฝ๐พ = 0

CBSE Class 12 Sample Paper for 2022 Boards (MCQ Based - for Term 1)
CBSE Class 12 Sample Paper for 2022 Boards (MCQ Based - for Term 1)
Last updated at Dec. 16, 2024 by Teachoo
Transcript
Question 40 Given that A = [โ 8(๐ผ&๐ฝ@๐พ&โ๐ผ )] and A2 = 3I, then : a) 1 + ๐ผ2 + ๐ฝ๐พ = 0 b) 1 โ ๐ผ2 โ ๐ฝ๐พ = 0 c) 3 โ ๐ผ2 โ ๐ฝ๐พ = 0 d) 3 + ๐ผ2 + ๐ฝ๐พ = 0 Given A2 = 3I [โ 8(๐ผ&๐ฝ@๐พ&โ๐ผ)] [โ 8(๐ผ&๐ฝ@๐พ&โ๐ผ)] = 3I [โ 8(๐ผ(๐ผ)+๐ฝ(๐พ)&๐ผ(๐ฝ)+๐ฝ(โ๐ผ)@๐พ(๐ผ)+(โ๐ผ)๐พ&๐พ(๐ฝ)+(โ๐ผ)(โ๐ผ))] = 3 [โ 8(1&0@0&1)] [โ 8(๐ถ^๐+๐ท๐ธ&๐@๐&๐ถ^๐+๐ท๐ธ)] = [โ 8(๐&๐@๐&๐)] Thus, ๐ถ^๐โคถ7+๐ท๐ธ = 3 0 = 3 โ ๐ผ^2โ๐ฝ๐พ 3 โ ๐ผ2 โ ๐ฝ๐พ = 0 So, the correct answer is (C)