Home
Class 11
MATHS
If 1 lies between the roots of equation ...

If 1 lies between the roots of equation `y^2 - my +1 = 0` and [x] denotes the integral part of x, then `[((4|x|)/(x^2+16))^m]`where `x in R` is equal to

A

0

B

1

C

2

D

undefined

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem step by step, we need to analyze the quadratic equation and the conditions given. ### Step 1: Analyze the quadratic equation The given quadratic equation is: \[ y^2 - my + 1 = 0 \] ### Step 2: Condition for roots We know that 1 lies between the roots of the quadratic equation. For this to happen, two conditions must be satisfied: 1. The discriminant must be greater than 0 (indicating two distinct roots). 2. The value of the quadratic at \( y = 1 \) must be less than 0 (indicating that 1 is between the roots). ### Step 3: Calculate the discriminant The discriminant \( D \) of the quadratic equation is given by: \[ D = m^2 - 4 \cdot 1 \cdot 1 = m^2 - 4 \] For the roots to be real and distinct, we require: \[ D > 0 \] Thus, we have: \[ m^2 - 4 > 0 \] This implies: \[ m > 2 \quad \text{or} \quad m < -2 \] ### Step 4: Evaluate the function at \( y = 1 \) Next, we evaluate the quadratic at \( y = 1 \): \[ f(1) = 1^2 - m \cdot 1 + 1 = 2 - m \] For 1 to lie between the roots, we need: \[ f(1) < 0 \] Thus: \[ 2 - m < 0 \] This implies: \[ m > 2 \] ### Step 5: Combine the conditions From the two conditions derived: 1. \( m > 2 \) 2. \( m < -2 \) The common area is: \[ m > 2 \] ### Step 6: Analyze the expression We need to evaluate: \[ \left[ \left( \frac{4 |x|}{x^2 + 16} \right)^m \right] \] where \([x]\) denotes the integral part of \(x\). ### Step 7: Find the range of the expression Since \( x^2 + 16 \) is always positive, we can analyze the expression: \[ \frac{4 |x|}{x^2 + 16} \] - The maximum value occurs when \( x = 0 \): \[ \frac{4 \cdot 0}{0^2 + 16} = 0 \] - As \( |x| \) increases, the value of \( \frac{4 |x|}{x^2 + 16} \) approaches 0. ### Step 8: Determine the limits The expression \( \frac{4 |x|}{x^2 + 16} \) is always positive and less than or equal to 1 for all \( x \) in \( \mathbb{R} \). Therefore, when raised to the power \( m \) (where \( m > 2 \)), the expression will also be between 0 and 1. ### Step 9: Evaluate the integral part Since: \[ 0 < \left( \frac{4 |x|}{x^2 + 16} \right)^m < 1 \] The integral part of any number between 0 and 1 is: \[ \left[ \left( \frac{4 |x|}{x^2 + 16} \right)^m \right] = 0 \] ### Final Answer Thus, the final answer is: \[ \boxed{0} \]

To solve the problem step by step, we need to analyze the quadratic equation and the conditions given. ### Step 1: Analyze the quadratic equation The given quadratic equation is: \[ y^2 - my + 1 = 0 \] ### Step 2: Condition for roots We know that 1 lies between the roots of the quadratic equation. For this to happen, two conditions must be satisfied: ...
Promotional Banner

Topper's Solved these Questions

  • QUADRATIC EXPRESSIONS AND EQUATIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Section II - Assertion Reason Type|22 Videos
  • QUADRATIC EXPRESSIONS AND EQUATIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Exercise|138 Videos
  • QUADRATIC EXPRESSIONS AND EQUATIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|50 Videos
  • PROBABILITY

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|45 Videos
  • SEQUENCES AND SERIES

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|59 Videos

Similar Questions

Explore conceptually related problems

If {x} denotes the fractional part of x, then int_(0)^(x)({x}-(1)/(2)) dx is equal to

If 2 lies between the roots of the equation t ^(2) - mt +2 =0,(m in R) then the value of [((2 |x|)/(9+x ^(2)))^(m)] is: (where [.] denotes greatest integer function)

If 2 lies between the roots of the equation t ^(2) - mt +2 =0,(m in R) then the value of [((2 |x|)/(9+x ^(2)))^(m)] is: (where [.] denotes greatest integer function)

If both the roots of the equation 4x^(2)-2x+m=0 lie in the interval (-1, 1) , then

if f(x) ={x^(2)} , where {x} denotes the fractional part of x , then

Show that: int_0^[[x]] (x-[x])dx=[[x]]/2 , where [x] denotes the integral part of x .

If both roots of the equation x^2-(m+1)x+(m+4)=0 are negative then m equals

If both roots of the equation x^2-2ax + a^2-1=0 lie between (-2,2) then a lies in the interval

int_0^1 [x^2-x+1]dx , where [x] denotes the integral part of x , is (A) 1 (B) 0 (C) 2 (D) none of these

If [x] denotes the integral part of x and f(x)=min(x-[x],-x-[-x]) show that: int_-2^2f(x)dx=1

OBJECTIVE RD SHARMA ENGLISH-QUADRATIC EXPRESSIONS AND EQUATIONS -Section I - Solved Mcqs
  1. Let f(x) = x^(3) + 3x^(2) + 9x + 6 sin x then roots of the equation (1...

    Text Solution

    |

  2. The number of integral values of a for which x^(2) - (a-1) x+3 = 0 has...

    Text Solution

    |

  3. If 1 lies between the roots of equation y^2 - my +1 = 0 and [x] denote...

    Text Solution

    |

  4. If a ,b ,c ,d are four consecutive terms of an increasing A.P., then t...

    Text Solution

    |

  5. If ax^(2)+bx+c=0, a ne 0, a, b, c in R has distinct real roots in (1,2...

    Text Solution

    |

  6. If the equation ax^(2) + bx + 6 = 0 has real roots, where a in R, b in...

    Text Solution

    |

  7. If a and b are distinct positive real numbers such that a, a(1), a(2),...

    Text Solution

    |

  8. The roots of ax^(2) +bx +c =0 " whose " a ne 0, b ,c in R , " are non...

    Text Solution

    |

  9. If alpha and beta are non-real, then condition for x^(2) + alpha x + b...

    Text Solution

    |

  10. If a gt 1 , then the roots of the equation (1-a)x^(2)+3ax-1=0 are

    Text Solution

    |

  11. If a, b in R, then the equation x^(2) - abx - a^(2) = 0 has

    Text Solution

    |

  12. The set of real values of a for which the equation x^(2) = a(x+a) has ...

    Text Solution

    |

  13. If the equations a x^2+b x+c=0 and x^3+3x^2+3x+2=0 have two common roo...

    Text Solution

    |

  14. if cos^4x+sin^2x-p=0 has real solutions then

    Text Solution

    |

  15. If a. 3^(tanx) + a. 3^(-tanx) - 2 = 0 has real solutions, x != pi/2 , ...

    Text Solution

    |

  16. If a, b are the real roots of x^(2) + px + 1 = 0 and c, d are the real...

    Text Solution

    |

  17. If a and 4a + 3b + 2c have same sign. Then, ax^(2) + bx + c = 0(a ne 0...

    Text Solution

    |

  18. Let f(x) =ax^(2) + bx + c and f(-1) lt 1, f(1) gt -1, f(3) lt -4 and a...

    Text Solution

    |

  19. The equations x^2+b^2=1-2bx and x^2+a^2=1-2ax have only oneroot in com...

    Text Solution

    |

  20. Total number of integral values of a such that x^2 + ax + a + 1 = 0 ha...

    Text Solution

    |