Practice Question On Matrix and determinant | CBSE | IITJEE | MAINS | ADVANCED | NDA | AIRFORCE | 31-45
Matrix and determinant Question no. 31 If A= , then A 100 = looks_one 2 100 A looks_two 2 99 A looks_3 2 101 A looks_4 None of these Answer Option looks_two 2 99 A Solution Solution : Characteristic eqaution : (1- λ) 2 - 1 = 0 λ 2 + 1 - 2λ - 1 = 0 λ 2 - 2λ = 0 A 2 = 2A A 3 = 2A 2 = 2 2 A A 4 = 2A 3 = 2 3 A . . . . A 100 = 2 99 A Question no. 32 Matrix A= is invertible for looks_one k=1 looks_two k=0 looks_3 k=-1 looks_4 All real k Answer option looks_two k=0 Solution Solution : For Invertible , |A| ≠ 0 1(1) - k(k) ≠ 0 k 2 ≠ 1 K ≠ 1 , -1 Question no. 33 If , then values of x,y,z,w are looks_one 2,2,3,4 looks_two 2,3,1,2 looks_3 3,3,0,1 looks_4 None of these Answer option looks_one 2,2,3,4 Solution Solution : x+ y = 4 .....[1] x- y = 0 .......[2] Solve [1] and [2] x = 2 , y = 2 2...