Determinants

If the system of equations : x+y+z=5 x+2y+3z=9 x+3y+ z= has infinitely many solutions, then the value of + is :

1. 16
2. 18
3. 19
4. 21

Let A= bmatrix1 & 2 & 7\ 4 & -2 & 8\ 3 & 8 & -7 bmatrix and (A- I)=0, where is a real number. If the largest possible value of is p, then the circle (x-p)2+(y-2p)2=320, intersects the co-ordinate axes at

1. 1 point
2. 2 points
3. 3 points
4. 4 points

Let , R be such that the system of linear equations x+2y+z=5 2x+y+ z=5 8x+4y+ z=18 has no solution. Then is equal to :

1. -4
2. 4
3. 8
4. -8

If the system of equations x+5y+6z=4, 2x+3y+4z=7, x+6y+az=b has infinitely many solutions, then the point (a, b) lies on the line

1. y-x=3
2. x-y=3
3. x+y=11
4. x+y=12

Let P = [pij] and Q = [qij] be two square matrices of order 3 such that qij = 2(i+j-1)pij and (Q) = 210. Then the value of ( adj( adj P)) is:

1. 81
2. 16
3. 124
4. 32

Let f(x) = 7x10 + 9x8(1 + x2 + 2x9)2 dx, x > 0, x 0 f(x) = 0 and f(1) = 14. If A = bmatrix 0 & 0 & 1 \ 14 & f'(1) & 1 \ 2 & 4 & 1 bmatrix and B = adj(adj A) be such that |B| = 81, then 2 is equal to

1. 2
2. 4
3. 3
4. 1

Among the statements : I: If vmatrix 1 & & \ & 1 & \ & & 1 vmatrix = vmatrix 0 & & \ & 0 & \ & & 0 vmatrix, then 2 + 2 + 2 = 32, and II: If vmatrix x2 + x & x + 1 & x - 2 \ 2x2 + 3x - 1 & 3x & 3x - 3 \ x2 + 2x + 3 & 2x - 1 & 2x - 1 vmatrix = px + q, then p2 = 196q2.

1. both are true
2. both are false
3. only I is true
4. only II is true

Let |A| = 6, where A is a 3 3 matrix. If |adj (3 adj (A2 adj(2A) ) ) | = 2m 3n, m, n N, then m + n is equal to .

The system of linear equations x + y + z = 6 2x + 5y + az = 36 x + 2y + 3z = b has :

1. unique solution for a = 8 and b = 16
2. infinitely many solutions for a = 8 and b = 14
3. infinitely many solutions for a = 8 and b = 16
4. unique solution for a = 8 and b = 14

Let A be a 3 3 matrix such that A + AT = O. If A bmatrix 1 \ -1 \ 0 bmatrix = bmatrix 3 \ 3 \ 2 bmatrix, A2 bmatrix 1 \ -1 \ 0 bmatrix = bmatrix -3 \ 19 \ -24 bmatrix and (adj(2 adj(A + I))) = (2) (3) (11) , , , are non-negative integers, then + + is equal to