Home
Class 12
MATHS
Find the number of roots of the equation...

Find the number of roots of the equation `log_(e)(1+x)-(tan^(-1)x)/(1+x)=0`

Text Solution

Verified by Experts

consider `f(x)=(1+x)log_(e)(1+x)tan^(-1),xgt-1`
`therefore f(x) =log_(e)(1+x)+1-(1)/(1+x^(2))`
`rArr f(x)=(1)/(1+x)+(2x)/(1+x^(2))^(2)`
`=(1)/(1+x)+(2x)/(1+x^(2))^(2)`
`rArr` f(x) =(1)
Sop f(x) is increasing
`therefore` For `xlt0 f(x)ltf(0)`
`rArr f(x)lt0`
`therefore` f(x)is decreasing function
`rArr f(x)gtf(0)`
`therefore f(x)gt0`
`rarr(1+x)log_(e)(1+x)-tan^(-1)xgt0`
`rarrf(x)gt0`
`rArr` f(x) is increasing
`rarr f(x)gtf(0)`
`rArr f(x)gt0`
`log_(e)(1+x)gt(tan^(-1))/(x+1)`
Hence f(x) is continuosu and increasing ,it crossses x axis only once at x=0
Therefore ,equation has only one real root x=0.
Promotional Banner

Topper's Solved these Questions

  • MONOTONICITY AND MAXIMA MINIMA OF FUNCTIONS

    CENGAGE|Exercise Illustration|2 Videos
  • MONOTONICITY AND MAXIMA MINIMA OF FUNCTIONS

    CENGAGE|Exercise Exercise 6.1|10 Videos
  • METHODS OF DIFFERETIATION

    CENGAGE|Exercise Question Bank|29 Videos
  • MONOTONOCITY AND NAXINA-MINIMA OF FUNCTIONS

    CENGAGE|Exercise Comprehension Type|6 Videos

Similar Questions

Explore conceptually related problems

Find the number of roots of the equation xlog_(e)x= 1 .

The number of roots of the equation 1+log_(2)(1-x)=2^(-x) , is

let f (x) = int _(0) ^(x) e ^(x-y) f'(y) dy - (x ^(2) -x+1)e ^(x) Find the number of roots of the equation f (x) =0.

Find number of roots of the equation x^(3)-log_(0.5) x = 0 .

Number of real roots of the equation e^(x-1)-x=0 is

Number of roots of the equation x^(2)e^(2-|x|)=1 is

Find the number of solution(s) of the equation log_(9)(x+1)*log_(2)(x+1)-log_(9)(x+1)-log_(2)(x+1)+1=0

The number of real roots of equation log_(e )x + ex = 0 is

Number of roots of the equation x^(2)-2x-log_(2)|1-x|=3 is

CENGAGE-MONOTONICITY AND MAXIMA MINIMA OF FUNCTIONS-JEE Advanced Previous Year
  1. Find the number of roots of the equation log(e)(1+x)-(tan^(-1)x)/(1+x...

    Text Solution

    |

  2. The function f:[0,3]vec[1, 29], defined by f(x)=2x^3-15 x^2+36 x+1, is...

    Text Solution

    |

  3. The number of points in (-oo,oo), for which x^2-xsinx-cosx=0, is 6 (b)...

    Text Solution

    |

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

    Text Solution

    |

  5. A rectangular sheet of fixed perimeter with sides having their lengths...

    Text Solution

    |

  6. The function f(x)=2|x|+|x+2|=||x|2|-2|x|| has a local minimum or a loc...

    Text Solution

    |

  7. For every pair of continuous functions f,g:[0,1]->R such that max{f(x)...

    Text Solution

    |

  8. Let a in R and let f: R to R be given by f(x) =x^(5) -5x+a. then

    Text Solution

    |

  9. Let f:R rarr(0,oo) and g:R rarr R be twice differntiable function such...

    Text Solution

    |

  10. If f:RR-> RR is a differentiable function such that f(x) > 2f(x) f...

    Text Solution

    |

  11. If f(x) = |{:( cos (2x) ,, cos ( 2x ) ,, sin ( 2x) ), ( - cos x,, cosx...

    Text Solution

    |

  12. Let f:(0,pi)rarrR be a twice differentiable fucntion such that lim(tra...

    Text Solution

    |

  13. Let f[0, 1] -> R (the set of all real numbers be a function.Suppose t...

    Text Solution

    |

  14. If the function d^(-x) f(X) assumes its minimum in the interval [0,1] ...

    Text Solution

    |

  15. Let f be a function defined on R (the set of all real numbers) such th...

    Text Solution

    |

  16. Let I RvecI R be defined as f(x)=|x|++x^2-1|dot The total number of po...

    Text Solution

    |

  17. Let p(x) be a real polynomial of least degree which has a local maximu...

    Text Solution

    |

  18. A cylindrica container is to be made from certain solid material with ...

    Text Solution

    |