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Relations And Functions

Question
CBSEENMA12036133

If for  x ∈ (0, 1/4)  the derivatives tan to the power of negative 1 end exponent space open parentheses fraction numerator 6 straight x square root of straight x over denominator 1 minus 9 straight x cubed end fraction close parentheses space is space square root of straight x. end root space straight g left parenthesis straight x right parenthesis comma then g(x) is equals to 

  • fraction numerator 3 over denominator 1 plus 9 straight x cubed end fraction
  • fraction numerator 9 over denominator 1 plus 9 straight x cubed end fraction
  • fraction numerator 3 straight x square root of straight x over denominator 1 minus 9 straight x cubed end fraction
  • fraction numerator 3 straight x over denominator 1 minus 9 straight x cubed end fraction

Solution

B.

fraction numerator 9 over denominator 1 plus 9 straight x cubed end fraction Let space straight y space equals space tan to the power of negative 1 end exponent space open parentheses fraction numerator 6 straight x space square root of 3 over denominator 1 minus 9 straight x cubed end fraction close parentheses space where space straight x space element of open parentheses 0 comma 1 fourth close parentheses
equals tan to the power of negative 1 end exponent space open parentheses fraction numerator 2. left parenthesis 3 straight x to the power of 3 divided by 2 end exponent right parenthesis over denominator 1 minus left parenthesis 3 straight x to the power of 3 divided by 2 end exponent right parenthesis end fraction close parentheses space space equals space 2 space tan to the power of negative 1 end exponent space left parenthesis 3 straight x to the power of 3 divided by 2 end exponent right parenthesis

As space 3 straight x to the power of 3 divided by 2 end exponent space element of space open parentheses 0 comma 3 over 8 close parentheses
therefore space dy over dx space equals space 2 space straight x space fraction numerator 1 over denominator 1 plus 9 straight x cubed end fraction space straight x space 3 space straight x 3 over 2 space straight x space space left parenthesis straight x to the power of 1 divided by 2 end exponent right parenthesis
space equals space fraction numerator 9 over denominator 1 plus 9 straight x cubed end fraction square root of straight x
therefore space straight g left parenthesis straight x right parenthesis space equals space fraction numerator 9 over denominator 1 plus 9 straight x cubed end fraction

Some More Questions From Relations and Functions Chapter

If a matrix A has 12 elements, what arc the possible orders it can have 7 What if it has 7 elements ?

Let A be the set of all students of a boys school. Show that the relation R in A given by R = {(a, b) : a is sister of b} is the empty relation and R’ = {(a, b) : the difference between heights of a and b is less than 3 meters} is the universal relation.

Show that the relation R in the set {1, 2, 3} given by R = {(1, 1), (2, 2), (3, 3), (1, 2), (2, 3)} is reflexive but neither symmetric nor transitive.

Show that the relation R in the set {1, 2, 3} given by R = {(1, 2), (2, 1)} is symmetric but neither reflexive nor transitive.

Give an example of a relation which is

(i) Symmetric but neither reflexive nor transitive.
(ii) Transitive but neither reflexive nor symmetric.
(iii) Reflexive and symmetric but not transitive.
(iv) Reflexive and transitive but not symmetric.
(v) Symmetric and transitive but not reflexive.

Let L be the set of all lines in a plane and R be the relation in L defined as R = {(L1, L2) : L1 is perpendicular to L2}. Show that R is symmetric but neither reflexive nor transitive.

 Determine whether each of the following relations are reflexive, symmetric and transitive :

(i) Relation R in the set A = {1, 2, 3,....., 13, 14} defined as

R = {(x, y) : 3 x – y = 0}

(ii) Relation R in the set N of natural numbers defined as R = {(x, y) : y = x + 5 and x < 4} (iii) Relation R in the set A = {1, 2, 3, 4, 5, 6} as R = {(x,y) : y is divisible by x} (iv) Relation R in the set Z of all integers defined as R = {(x,y) : x – y is an integer}

(v) Relation R in the set A of human beings in a town at a particular time given by
(a)    R = {(x, y) : x and y work at the same place}
(b)    R = {(x,y) : x and y live in the same locality}
(c)    R = {(x, y) : x is exactly 7 cm taller than y}
(d)    R = {(x, y) : x is wife of y}
(e)    R = {(x,y) : x is father of y}

Check whether the relation R defined in the set {1, 2, 3, 4, 5, 6} as R = {(a, b) : b = a + 1} is reflexive, symmetric or transitive.

Show that the relation R in R defined as R = {(a, b) : a ≤ b}, is reflexive and transitive but not symmetric.