Home
Class 12
MATHS
Find the least value of n such that (n-2...

Find the least value of `n` such that `(n-2)x^2+x+n+4>0,AAx in R ,w h e r en in Ndot`

Text Solution

Verified by Experts

`(n-2)x^(2) + 8 x + n + 4 gt 0, AA x in `R
`rArr D = 64 - 4 (n- 2) (n + 4) lt 0 and n - 2 gt 0`
`rArr 16 - (n^(2) + 2n - 8) lt 0 and n gt 2`
`rArr n^(2) + 2n - 24 gt 0 and n gt 2`
`rArr (n + 6) (n - 4) gt 0 and n gt 2`
`rArr n gt 4 as n in N and n gt 2`
`rArr n ge 5`
Hence, the least value of n is 5.
Promotional Banner

Topper's Solved these Questions

  • THEORY OF EQUATIONS

    CENGAGE PUBLICATION|Exercise SOLVED EXAMPLES|14 Videos
  • THEORY OF EQUATIONS

    CENGAGE PUBLICATION|Exercise CONCEPT APPLICATION EXERCISE 2.1|3 Videos
  • THEORY OF EQUATIONS

    CENGAGE PUBLICATION|Exercise Multiple Correct Answer|6 Videos
  • STRAIGHT LINES

    CENGAGE PUBLICATION|Exercise ARCHIVES (NUMERICAL VALUE TYPE)|1 Videos
  • THREE DIMENSIONAL GEOMETRY

    CENGAGE PUBLICATION|Exercise All Questions|291 Videos

Similar Questions

Explore conceptually related problems

Find the least value of n such that (n-2)x^2+8x+n+4>0,AAx in R ,w h e r en in Ndot

Find the derivative of 2.x^n w.r.t.x .

Find the values of k for which |(x^2+k x+1)/(x^2+x+1)|<2,AAx in R

If 9^7+7^9 is divisible b 2^n , then find the greatest value of n ,w h e r en in Ndot

Find the value of i^n+i^(n-1)+i^(n-2)+i^(n-3) for all n in Ndot

If 9^7-7^9 is divisible by 2^n , then find the greatest value of n ,w h e r en in Ndot

Find the value of i^n+i^(n+1)+i^(n+2)+i^(n+3) for all n in Ndot

Fill in the blanks If 2+isqrt(3) is a root of the equation x^2+p x+q=0,w h e r epa n dq are real, then (p ,q)=(______,_____) .

Find the derivatives w.r.t. x : {f(x)}^(n)

Find the derivatives w.r.t. x : sec^(n)x

CENGAGE PUBLICATION-THEORY OF EQUATIONS-ILLUSTRATION
  1. Find the largest natural number a for which the maximum value of f(x)=...

    Text Solution

    |

  2. Let f(x)=a x^2+b x+c be a quadratic expression having its vertex at (3...

    Text Solution

    |

  3. Find the least value of n such that (n-2)x^2+x+n+4>0,AAx in R ,w h e ...

    Text Solution

    |

  4. Given that a ,b ,c are distinct real numbers such that expressions a x...

    Text Solution

    |

  5. For a in R, if |x - a + 3| + |x-3a|=|2x - 4a +3 | is ture AA x inR. ...

    Text Solution

    |

  6. If c is positive and 2a x^2+3b x+5c=0 does not have any real roots, th...

    Text Solution

    |

  7. If a x^2+b x+6=0 does not have distinct real roots, then find the leas...

    Text Solution

    |

  8. A quadratic trinomial P(x)=a x^2+b x+c is such that the equation P(x)=...

    Text Solution

    |

  9. If the inequality (m x^2+3x+4+2x)//(x^2+2x+2)<5 is satisfied for all x...

    Text Solution

    |

  10. Find the values of k for which |(x^2+k x+1)/(x^2+x+1)|<2,AAx in R

    Text Solution

    |

  11. If x in R ,a n da ,b ,c are in ascending or descending order of magni...

    Text Solution

    |

  12. Let x^(2) - ( m - 3) x + m = 0 ( m in R) be a quadratic equation. Find...

    Text Solution

    |

  13. If alpha is a real root of the quadratic equation a x^2+b x+c=0a n dbe...

    Text Solution

    |

  14. The equation a x^2-b x+c=0 has real and positive roots. Prove that the...

    Text Solution

    |

  15. For what real values of a do the roots of the equation x^2-2x-(a^2-1)=...

    Text Solution

    |

  16. If (x^2+x=2)62=(a-3)(x^2+x+1)(x^2+x+2)+(a-4)(x^2+x+1)^2=0 has at least...

    Text Solution

    |

  17. Find all real value of a for which the equation x^4 + (a - 1)x^3+ x^2 ...

    Text Solution

    |

  18. If the equation sin ^(2) x - k sin x - 3 = 0 has exactly two distinct ...

    Text Solution

    |

  19. Find all the value of m for which the equation sin^2x+(m-3)sinx+m=0 ha...

    Text Solution

    |

  20. If 2a+3b+6c=0, then prove that at least one root of the equation a x^2...

    Text Solution

    |