Home
Class 12
MATHS
Let f(x)=x^2+(1/x^2) and g(x)=x-1/x xin...

Let `f(x)=x^2+(1/x^2)` and `g(x)=x-1/x` `xinR-{-1,0,1}`. If `h(x)=(f(x)/g(x))` then the local minimum value of `h(x)` is: (1) 3 (2) `-3` (3) `-2sqrt(2)` (4) `2sqrt(2)`

A

`2sqrt(2)`

B

3

C

-3

D

`-2sqrt(2)`

Text Solution

Verified by Experts

The correct Answer is:
1

`h(x) =(x^(2)+(1)/(x^(2))/(x-(1)/(x))=(x-(1)/(x))^(2)+2)/(x-(1)/(x))=(x-(1)/(x))+(2)/(x-(1)/(x))`
Let `x-(1)/(x)=z`
For local minimum value of `h(x) let zgt0`
`therefore h(x) =z+(2)/(z)=sqrt(z)-sqrt(2)/(z)^(2)+2sqrt(2)ge2sqrt(2)`
So local minimum value of h(x) is `2sqrt(2)`
if `zlt0` then
`h(x)=-[-a-(2)/(z)]=-[sqrt(-z)-sqrt(2)/(-z)]^(2)-2sqrt(2)le-2sqrt(2)`
So `-2sqrt(2)` is locall maximum value of h(x)
Promotional Banner

Topper's Solved these Questions

  • MONOTONICITY AND MAXIMA MINIMA OF FUNCTIONS

    CENGAGE ENGLISH|Exercise Linked comprehension Type|2 Videos
  • MONOTONICITY AND MAXIMA MINIMA OF FUNCTIONS

    CENGAGE ENGLISH|Exercise Linked comprehension type|50 Videos
  • MONOTONICITY AND MAXIMA MINIMA OF FUNCTIONS

    CENGAGE ENGLISH|Exercise Numerical Value Type|24 Videos
  • METHODS OF DIFFERENTIATION

    CENGAGE ENGLISH|Exercise Single Correct Answer Type|46 Videos
  • MONOTONOCITY AND NAXINA-MINIMA OF FUNCTIONS

    CENGAGE ENGLISH|Exercise Comprehension Type|6 Videos

Similar Questions

Explore conceptually related problems

Let f(x)=x^2+ 1/x^2 and g(x)=x-1/x, x in R-{-1,0,1} . If h(x) = f(x)/g(x) then the local minimum value of h(x) is: (1) 3 (2) -3 (3) -2sqrt(2) (4) 2sqrt(2)

let f(x)=(x^2-1)^n (x^2+x-1) then f(x) has local minimum at x=1 when

If f(x)=|x-2|+x^(2)-1 and g(x)+f(x)=x^(2)+3 , find the maximum value of g(x) .

If int(x-1)/(x^2sqrt(2x^2-2x-1))dx = sqrt(f(x))/g(x) +c then the value of f(x) and g(x) is

If f(x) = x^(2) and g(x) = (1)/(x^(3)) . Then the value of (f(x)+g(x))/(f(-x)-g(-x)) at x = 2 is

If the function f(x)=x^3+e^(x/2) and g(x)=f ^(−1)(x) , then the value of g ′ (1) is

Let f(x)=x^2+xg^2(1)+g^''(2) and g(x)=f(1).x^2+xf'(x)+f''(x), then find f(x) and g(x).

If f(x)=sqrt(x^(2)-1) and g(x)=(10)/(x+2) , then g(f(3)) =

If f(x)=cos^(-1)(x^((3)/(2))-sqrt(1-x-x^(2)+x^(3))),AA 0 le x le 1 then the minimum value of f(x) is

Let f:""R vec R be defined by f(x)={k-2x , if""xlt=-1 (-2x+3),x >-1} . If f has a local minimum at x=-1 , then a possible value of k is (1) 0 (2) -1/2 (3) -1 (4) 1