Home
Class 12
MATHS
Let f(x)=1-x-x^(3). Then, the real value...

Let `f(x)=1-x-x^(3)`. Then, the real values of x satisfying the inequality,
`1-f(x)-f^(3)(x) gt f(1-5x)`, are

A

(0,2)

B

(-2,2)

C

`(-2,1) cup(1, oo)`

D

`(-oo , -2)cup (0,2)`

Text Solution

Verified by Experts

The correct Answer is:
D

We have `f(x)=1-x-x^3`
`therefore f(x) =-1 -3x^2 lt 0 " for all " x in R `
`rArr f(x)=-1-3x^2 lt 0 for all x in R `
Now `1- f(x)=f^3(x) gt f(1-5x)`
`rArr f(f(x)) gt f(1-5x)`
`f(x) gt 1-5x`
`rArr 1-x-x^3 gt 1-5x`
`rArr x^3-4x lt 0`
`rArr x(x-2)(x+2) lt 0 `
`rArr x in (-oo,-2)cup (0,2)`
Promotional Banner

Topper's Solved these Questions

  • INCREASING AND DECREASING FUNCTIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Section II - Assertion Reason Type|8 Videos
  • INCREASING AND DECREASING FUNCTIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Exercise|36 Videos
  • INCREASING AND DECREASING FUNCTIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|18 Videos
  • HEIGHTS AND DISTANCES

    OBJECTIVE RD SHARMA ENGLISH|Exercise Exercise|45 Videos
  • INDEFINITE INTEGRALS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|30 Videos

Similar Questions

Explore conceptually related problems

Let f(x)=1-x-x^3 .Find all real values of x satisfying the inequality, 1-f(x)-f^3(x)>f(1-5x)

Let f(x)=1-x-x^3 .Find all real values of x satisfying the inequality, 1-f(x)-f^3(x)>f(1-5x)

If f(x) = x^2 - 3x + 4 , then find the values of x satisfying the equation f(x) = f(2x + 1) .

If f is symmetrical about x = 1, find the real values of x satisfying the equation f(x)=f((x+1)/(x+2)) .

Let f(x)=x+1 and phi(x)=x-2. Then the value of x satisfying |f(x)+phi(x)|=|f(x)|+|phi(x)| are :

If f(x)= -x^(3)-3x^(2)-2x+a,a in R then the real values of x satisfying f(x^(2)+1)gtf(2x^(2)+2x+3) will be

Let f(x) be a real valued function satisfying the relation f(x/y) = f(x) - f(y) and lim_(x rarr 0) f(1+x)/x = 3. The area bounded by the curve y = f(x), y-axis and the line y = 3 is equal to

Let f(x)=30-2x -x^3 , the number of the positive integral values of x which does satisfy f(f(f(x)))) gt f(f(-x)) is _______.

Let f(x)=a^x-xlna , a>1. Then the complete set of real values of x for which f'(x)>0 is

If f(x) = (x + 1)/(x-1) , then the value of f{f(3)} is :

OBJECTIVE RD SHARMA ENGLISH-INCREASING AND DECREASING FUNCTIONS-Section I - Solved Mcqs
  1. If a lt 0 and f(x)=e^(ax )+ e^(-ax) is monotonically decreasing . F...

    Text Solution

    |

  2. If f(x)= underset(x)overset(x^2)int1/((log t)^2)dt ,x ne 1 then f(x)is...

    Text Solution

    |

  3. The interval in which the function f(x)=underset(0)overset(x)int((t...

    Text Solution

    |

  4. If f(x)=x^3+bx^2+cx+d and 0<b^2<c, then

    Text Solution

    |

  5. For the function f(x)=x cos ""1/x, x ge 1 which one of the following i...

    Text Solution

    |

  6. If the function g:(-oo,oo)rarr(-(pi)/(2),(pi)/(2)) is given by g(u)=...

    Text Solution

    |

  7. Consider the function f:(-oo, oo) -> (-oo ,oo) defined by f(x) =(x^2...

    Text Solution

    |

  8. Consider the polynomial f(x)=1 + 2x + 3x^2 +4x^3 for all x in R So...

    Text Solution

    |

  9. Consider the polynomial f(x) = 1+2x+3x^(2)+4x^(3) Let s be the sum...

    Text Solution

    |

  10. If f(x)=x^(3/2)(3x-10),xgeq0, then f(x) is increasing in .

    Text Solution

    |

  11. Let f(x) = log (sin x+ cos x), x in x (-pi/4,(3pi)/(4)) Then f is st...

    Text Solution

    |

  12. Let f(x) = (1-x)^(2) sin^(2)x+ x^(2) for all x in IR and let g(x) = un...

    Text Solution

    |

  13. f(x)=x|logex|,x gt 0 is monotonically decreasig in

    Text Solution

    |

  14. Let F:RtoR be a thrice differntiable function. Suppose that F(1)=0,F(3...

    Text Solution

    |

  15. Let f(x)=1-x-x^(3). Then, the real values of x satisfying the inequali...

    Text Solution

    |

  16. Let g(x)=f(sin x)+ f(cosx), then g(x) is decreasing on:

    Text Solution

    |

  17. Let f(x) be a monotonic polynomial of (2m-1) degree where m in N, then...

    Text Solution

    |

  18. Let f(x) =sin^4x+cos^4x. Then f is increasing function in the interval

    Text Solution

    |

  19. If f:R->R is a twice differentiable function such that f''(x) > 0 for ...

    Text Solution

    |

  20. If f:R is a differentiable fucntion such that f(x) gt 2f(x) for all x...

    Text Solution

    |