help ii1x 3 matrix a desCA a the reduced res brs rankANA as
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Solution
Q1) If det(A) = a, then det(cA) = c^n * a
where n represents the dimension of square matrix
Given det(A) = 3
det(5A) = 5^3 * 3 = 125 * 3 = 375
Hence the det(5A) will be equal to 375
Q2)
Rank of the matrix is equal to 3, since there are three independent columns and Null space will be equal to 1
Since the rank(A) + Null(A) = number of columns
Q3)
Expanding th determinant across the first row we get
det(A) = 1(3*5-0) + 2(0*6-0*5) + 3(0*0-3*0)
det(A) = 1(15-0) + 2(0-0) + 3(0-0)
det(A) = 15
Q4)
Det(A - pI) = 0
(2-p)(1-p) - 0 = 0
(2-p)(1-p) = 0
Hence the eigen values are 1 and 2
adjoint of the matrix will be [1,-2;0,2]
