Business Mathematics
251. A triangular matrix can be
- Upper triangular
- Lower triangular
- Both
- None
Correct answer: (C)
Both
252. If A = cosØ -sinØ then A+ A = I, if the value of Ø sin Ø cosØ
- π/6
- π/3
- π
- 3π/2
Correct answer: (B)
π/3
253. Two matrices A and B are said to be equal if,
- A and B are not of same order
- A and B are of symmetric order
- A and B are of null order
- A and B are of same order
Correct answer: (D)
A and B are of same order
254. If the matrix A is both symmetric and skew symmetric, then
- A is a diagonal matrix
- A is a zero matrix
- A is a square matrix
- None of these
Correct answer: (B)
A is a zero matrix
255. The area of a triangle whose vertices are ( 3, 8), ( -4, 2) and (5 ,1) is
- 63/2
- 51/2
- 61/2
- 55/2
Correct answer: (C)
61/2
256. If area of a triangle is 35sq.units with vertices (2, -6), (5,4) and (k, 4). Then k is
- 12
- -2
- -12, -2
- 12, -2
Correct answer: (D)
12, -2
257. Solve -x –y +z = -2
3x +2y -2z =7
x +3y -3z =0
- y and z are linearly dependent
- x, y, z are independent
- x ,y and z are dependent
- None of the above
Correct answer: (A)
y and z are linearly dependent
258. The equation ax -3y +5z = 4 is inconsistent for
x –ay +3z =2
9x -7y +8az =0
- a =2
- a= 3
- a =4
- a =5
Correct answer: (A)
a =2
259. Solve x +y +z =6 using matrix inversion method
x +2y +3z =14
-x +y –z = -2
a)x=2, y=3, z=1
- x=1, y=2, z=3
- x=1, y=3,z=5
- x=2, y=1, z=3
Correct answer: (B)
x=1, y=3,z=5
260. Solve x -2y +z =1
3x +y -2z =4
y -z =1
- x=0, y=-2, z=-3
- x=1, y=-1, z=3
- x=-2, y=0, z=-3
- x=2, y=-1, z=0
Correct answer: (A)
x=0, y=-2, z=-3