Linear Programming

More Topic from Mathematics

Question 1

If x is real, the maximum value of fraction numerator 3 straight x squared space plus 9 straight x space plus 17 over denominator 3 straight x squared space plus 9 straight x space plus 7 end fraction space is

  • 1/4

  • 41

  • 1

  • 17/7

Solution

B.

41

straight y space equals space fraction numerator 3 straight x squared space plus 9 straight x space plus 17 over denominator 3 straight x squared space plus 9 straight x space plus 7 end fraction
3 straight x squared space left parenthesis straight y minus 1 right parenthesis space plus 9 straight x left parenthesis straight y minus 1 right parenthesis space plus 7 straight y space minus 17 space equals space 0
straight D greater or equal than 0 space because space straight x space is space real
81 space left parenthesis straight y equals 1 right parenthesis squared space minus 4 straight x cubed left parenthesis straight y minus 1 right parenthesis left parenthesis 7 straight y minus 17 right parenthesis greater or equal than 0
rightwards double arrow space left parenthesis straight y minus 1 right parenthesis left parenthesis straight y minus 41 right parenthesis less or equal than 0
rightwards double arrow space 1 less or equal than space straight y less or equal than 41
Question 2

The function straight f left parenthesis straight x right parenthesis space equals straight x over 2 space plus 2 over straight x has a local minimum at

  • x = 2

  • x = −2

  • x = 0

  • x=1

Solution

A.

x = 2

straight x over 2 space plus 2 over straight x space space is space of space the space form space straight x plus 1 over straight x greater or equal than 2& equality holds for x = 1
Question 3

The line L1: y = x = 0 and L2: 2x + y = 0 intersect the line L3: y + 2 = 0 at P and Q respectively. The bisectorof the acute angle between L1 and L2 intersects L3 at R.
Statement-1: The ratio PR: RQ equals 2√2:√5
Statement-2: In any triangle, the bisector of an angle divides the triangle into two similar triangles.

  • Statement-1 is true, Statement-2 is true ; Statement-2 is correct explanation for Statement-1

  • Statement-1 is true, Statement-2 is true ; Statement-2 is not a correct explanation for Statement-1

  • Statement-1 is true, Statement-2 is false

  • Statement-1 is false, Statement-2 is true

Solution

C.

Statement-1 is true, Statement-2 is false


∴ AD : DB = 2√2:√5
∴ OD is angle bisector of angle AOB
∴ Statement: 1 true
Statement : 2 false