Lista de Exercicios Matematica-64

Text Material Preview

Quest Tutorials
North Delhi : E-16/289, Sector-8, Rohini, New Delhi. Ph. 65395439
[10]
Quest
Q.61 If D = 
1 1
1 1
2
2
2
2 2
z z
x y
z
y z
x x x
y y z
x z
x y z
xz
y x y
xz
−
+
−
+
−
+ + +
−
+
( )
( )
( ) ( )
 then, the incorrect statement is
(A) D is independent of x (B) D is independent of y
(C) D is independent of z (D) D is dependent on x, y, z
Q.62 If every element of a square non singular matrix A is multiplied by k and the new matrix is denoted by B
then | A–1| and | B–1| are related as
(A) | A–1| = k | B–1| (B) | A–1| = 
k
1
| B–1| (C) | A–1| = kn | B–1| (D) | A–1| = k–n | B–1|
where n is order of matrices.
Q.63 If f ′ (x) = 
pn2mxpn2mxn2mx
pnpnn
pmxpmxmx
−++++
−+
+−
 then y = f(x) represents
(A) a straight line parallel to x- axis (B) a straight line parallel to y- axis
(C) parabola (D) a straight line with negative slope
Q.64 Let A = 








−
−
111
312
111
 and 10B = 








−
α−
321
05
224
. If B is the inverse of matrix A, then α is
(A) – 2 (B) – 1 (C) 2 (D) 5
Q.65 If D(x) = 
32
32
32
)1x()1x(x
)1x(x1x
x)1x(1x
++
+−
−−
 then the coefficient of x in D(x) is
(A) 5 (B) – 2 (C) 6 (D) 0
Q.66 The set of equations
λx – y + (cosθ) z = 0
3x + y + 2z = 0
(cosθ)x + y + 2z = 0
0