Home
Class 12
MATHS
Find the values of a for which one root ...

Find the values of `a` for which one root of equation `(a-5)x^(2)-2ax+a-4=0` is smaller than 1 and the other greater than 2.

Text Solution

Verified by Experts

The given equation can be written as
`x^(2)-((2a)/(a-5))x+((a-4)/(a-5))=0,a!=5`
Now let `f(x)=x^(2)-((2a)/(a-5))x+((a-4)/(a-5))`
As 1 and 2 lie between the roots of `f(x)=0`, we can take `Dgt0,1.f(1)lt0` and `1.f(2)lt0`.
(i) Consider `Dgt0`
`(-((2a)/(a-5)))^(2)-4.1.((a-4)/(a-5))gt0`
`implies(36(a-20/9))/((a-5)^(2))gt0 [ :' a1=5]`
or `agt20/9`.......i
(ii) Consider `1.f(1)lt0`
`1^(2)-((2a)/(a-5))+((a-4)/(a-5))lt0implies9/((a-5))gt0` or `agt5`..........ii
(iii) Consider `1.f(2)lt0`
`4-(4a)/((a-5))+((a-4)/(a-5))lt0`
`implies((4a-20-4a+a-4))/((a-5))lt0implies((a-24))/((a-5))lt0`
Or `5 ltalt24`......iii
Hence the values of `a` satisfying Eqs (i),(ii) and (iii) at the same time are `a epsilon (5,24)`.
Promotional Banner

Topper's Solved these Questions

  • THEORY OF EQUATIONS

    ARIHANT MATHS|Exercise Exercise For Session 1|11 Videos
  • THEORY OF EQUATIONS

    ARIHANT MATHS|Exercise Exercise For Session 2|10 Videos
  • THE STRAIGHT LINES

    ARIHANT MATHS|Exercise Exercise (Questions Asked In Previous 13 Years Exam)|18 Videos
  • THREE DIMENSIONAL COORDINATE SYSTEM

    ARIHANT MATHS|Exercise Exercise (Questions Asked In Previous 13 Years Exam)|44 Videos

Similar Questions

Explore conceptually related problems

The values of a for which one root of the equation, x^(2)+(2a+1)x+(a-2)=0 is greater than 1 and the other root less than zero, is

The set of all value of a for which one root of equation x^2-ax+1=0 is less than unity and other greater than unity (A) (-oo,2) (B) (2,oo) (C) (1,oo) (D) none of these

Find the values of m for which roots of equation x^(2)-mx+1=0 are less than unity.

Find the set of all values of a for which the roots of the equation x^(2)-2ax+a^(2)+a-3=0 are less than 3

The values of lamda for which one root of the equation x^2+(1-2lamda)x+(lamda^2-lamda-2)=0 is greater than 3 and the other smaller than 2 are given by

Find all values of a for which atleast one of the roots of the equation x^(2)-(a-3)x+a=0 is greater than 2

Find interval of values of ' a ' for which one root of equation x^2+a^2(x+1)+(a-2)=0 is negative and the other root is positive

Find the value of k for which one root of the equation of x^(2)-(k+1)x+k^(2)+k-8=0 exceed 2 and other is smaller than 2.

Find the value of a for which one root of the quadratic equation (a^(2)-5a+3)x^(2)+(3a-1)x+2=0 is twice as large as the other.

ARIHANT MATHS-THEORY OF EQUATIONS-Exercise (Questions Asked In Previous 13 Years Exam)
  1. Find the values of a for which one root of equation (a-5)x^(2)-2ax+a-4...

    Text Solution

    |

  2. In the quadratic equation ax^2 + bx + c = 0. if delta = b^2-4ac and al...

    Text Solution

    |

  3. Let S denote the set of all polynomials P(x) of degree lt=2 such th...

    Text Solution

    |

  4. If the roots of x^2-b x+c=0 are two consecutive integers, then b^2-4c ...

    Text Solution

    |

  5. If the equation a(n)x^(n)+a(n-1)x^(n-1)+..+a(1)x=0, a(1)!=0, n ge2, ha...

    Text Solution

    |

  6. If both the roots of the quadratic equation x^2-2kx+k^2+k-5=0 are less...

    Text Solution

    |

  7. Let aa n db be the roots of the equation x^2-10 c x-11 d=0 and those o...

    Text Solution

    |

  8. Let a,b,c be the sides of a triangle. No two of them are equal and lam...

    Text Solution

    |

  9. All the values of m for whilch both the roots of the equation x^2-2m x...

    Text Solution

    |

  10. If the roots of the quadratic equation x^2+p x+q=0 are tan30^0a n dtan...

    Text Solution

    |

  11. Let alpha,beta be the roots of the equation x^2-p x+r=0 and alpha/2,2b...

    Text Solution

    |

  12. If the difference between the roots of the equation x^2+a x+1=0 is les...

    Text Solution

    |

  13. Let a, b, c, p, q be the real numbers. Suppose alpha,beta are the ...

    Text Solution

    |

  14. The quadratic equations x^2""6x""+""a""=""0""a n d""x^2""c x""+""6"...

    Text Solution

    |

  15. How many real solutions does the equation x^7+14 x^5+16 x^3+30 x-560=0...

    Text Solution

    |

  16. Suppose the cubic x^(3)-px+q has three distinct real roots, where pgt0...

    Text Solution

    |

  17. The smallest value of k, for which both the roots of the equation, x^2...

    Text Solution

    |

  18. If the roots of the equation b x^2+""c x""+""a""=""0 be imaginary, ...

    Text Solution

    |

  19. Q. Let p and q real number such that p!= 0,p^2!=q and p^2!=-q. if alph...

    Text Solution

    |

  20. Conder the function f(x)=1+2x+3x^2+4x^3 Let the sum of all distinct ...

    Text Solution

    |

  21. Let alpha and beta be the roots of x^2-6x-2=0 with alpha>beta if an=al...

    Text Solution

    |