Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Determinants

Question:

Match List I with List II.

List – I

List – II

 (A) 

 R = {(x, y) : x and y are student of the same school} 

 (I)

 Symmetric  

 (B)

 R = {(L1, L2) : L1 ⊥ L2, L1, L2 ∈ L, where L is a set of all lines} 

 (II)

 One - one

 (C)

 A function f : R → R defined by f(x) = 2 - 3x is  

 (III) 

 Bijective 

 (D)

 A function f : [0, 1] → R defined by f(x) = 1 + x2 is f : [0, 1] → R  

 (IV)

 Equivalence 

Choose the correct answer from the options given below :

Options:

A - I, B - IV, C - II, D - III

A - IV, B - I, C - III, D - II

A - I, B - IV, C - III, D - II

A - IV, B - I, C - II, D - III

Correct Answer:

A - IV, B - I, C - III, D - II

Explanation:

A. R = {(x, y) : x, y ∈ same school} 

so (x, x) ∈ R  for every x ∈ A          →     IV

(x, y) ∈ R ⇒ (y, x) ∈ R

(x, y) ∈ R  ,  (y, z) ∈ R ⇒ (x, x) ∈ R  equivalence

B. R = {(L1, L2) : L1 ⊥ L2  for  L1, L2 ∈ L

so (L1, L1) ∉ R as on line is perpendicular to itself

(L1, L2) ∈ R  ⇒  (L2, L1) ∈ R  (symmetric)         →    I

(L1, L2) ∈ R ,  (L2, L3) ∈ R

⇒ (L1, L3) ∉ R  as  L1 ⊥ L2   L2 ⊥ L3

⇒ L1 || L2

C. y = 2 - 3x → linear function

so  $\frac{2-y}{3} = x$ ⇒ for every y ∈ R        →     III

there event atleast one x

y1 = y2  ⇒  2 - 3x1 = 2 - 3x2

⇒ x1 = x2 ⇒ bijective

D. f : [0, 1] → R

y = 1 + x2 

so  $x = \sqrt{1-y}$

⇒ one, one        →    II

for y = 5 not defined but for every y, x is unique as x ∈ [0, 1]