Home
Class 12
MATHS
If alpha, beta and gamma are the roots o...

If `alpha, beta and gamma` are the roots of the equation `x^(3) + 3x^(2) - 24x + 1 = 0`
thebn find the value of `(3sqrt(alpha)+3sqrt(beta)+ 3sqrt(gamma)).`

Text Solution

Verified by Experts

`x^(3) + 3x^(2) + 3x + 1 = 27 x `
`(x + 1)^(3) = 27x`
Equation has roots `alpha, beta, and gamma`
`therefore (alpha + 1)^(3) = 27 alpha` (1)
Let `3sqrt(alpha)= y` . Then `alpha = y^(3)`
Now, (1) reduces to
`(y^(3) + 1)^(3) = 27y^(3)`
`rArr y^(3) + 1 = 3y`
`rArr y^(3) - 3y + 1 = 0`
This equation has roots `3sqrt(alpha),3sqrt(beta),3sqrt(gamma)`
`therefore 3sqrt(alpha)+3sqrt(beta)+3sqrt(gamma) = 0`
Promotional Banner

Topper's Solved these Questions

  • THEORY OF EQUATIONS

    CENGAGE|Exercise Exercise 2.1|3 Videos
  • THEORY OF EQUATIONS

    CENGAGE|Exercise Exercise 2.2|5 Videos
  • THEORY OF EQUATIONS

    CENGAGE|Exercise Comprehension|12 Videos
  • STRAIGHT LINES

    CENGAGE|Exercise JEE Advanced Previous Year|4 Videos
  • THREE DIMENSIONAL GEOMETRY

    CENGAGE|Exercise Question Bank|20 Videos

Similar Questions

Explore conceptually related problems

If alpha, beta and gamma are the roots of the cubic equation (x-1)(x^(2) + x + 3)=0 , then the value of alpha^(3) + beta^(3) + gamma^(3) is:

If alpha, beta and gamma the roots of the equation x^(3) + 3x^(2) - 4x - 2 = 0. then find the values of the following expressions: (i) alpha ^(2) + beta^(2) + gamma^(2) (ii) alpha ^(3) + beta^(3) + gamma^(3) (iii) (1)/(alpha)+(1)/(beta)+(1)/(gamma)

If alpha, beta, gamma are the roots of the equation x^(3) + x + 1 = 0 , then the value of alpha^(3) + beta^(3) + gamma^(3) , is

If alpha,beta,gamma are the roots of the equation x^(3)-px^(2)+qx-r=0 find the value of (beta+gamma)(gamma+alpha)(alpha+beta)

If alpha,beta,gamma are the roots of the equation x^(3)+px^(2)+qx+r=0, then find he value of (alpha-(1)/(beta gamma))(beta-(1)/(gamma alpha))(gamma-(1)/(alpha beta))

If alpha,beta,gamma are the roots of the equation 2x^(3)x^(2)+x-1=0 then alpha^(2)+beta^(2)+gamma^(2)=

If alpha,beta and gamma are the roots of the cubic equation 3x^(3)+2x^(2)+x-1=0 ,then the value of (alpha beta+beta gamma+gamma alpha) is (A) 3 (B) 2 (C) (1)/(2) (D) (1)/(3)

If alpha, beta ,gamma are the roots of the equation x ^(3) + 2x ^(2) - x+1 =0, then vlaue of ((2- alpha )(2-beta) (2-gamma))/((2+ alpha ) (2+ beta ) (2 + gamma)) is :

CENGAGE-THEORY OF EQUATIONS-Examples
  1. If alpha,beta,gamma are the roots of the equation x^3 + 4x +1=0 then (...

    Text Solution

    |

  2. Equations x^3+5x 62+p x+q=0a n dx 63+7x^2+p x+r=0 have two roots in co...

    Text Solution

    |

  3. If alpha, beta and gamma are the roots of the equation x^(3) + 3x^(2) ...

    Text Solution

    |

  4. If euation x^(3) + ax^(2) + bx + c = 0, where a, b, c in Q (a ne 1)....

    Text Solution

    |

  5. Solve the equation x^3-13 x^2+15 x+189=0 if one root exceeds the other...

    Text Solution

    |

  6. In equation x^4-2x^3+4x^2+6x-21=0 if two its roots are equal in mag...

    Text Solution

    |

  7. If b^2<2a c , then prove that a x^2+b x^2+c x+d=0 has exactly one real...

    Text Solution

    |

  8. If f(x)=x^2+b x^2+c x+da n df(0),f(-1) are odd integers, prove that f(...

    Text Solution

    |

  9. If x-c is a factor of order m of the polynomial f(x) of degree n(1<m<n...

    Text Solution

    |

  10. What is the minimum height of any point on the curve y=x^2-4x+6 above ...

    Text Solution

    |

  11. What is the minimum height of any point on the curve y=x^2+6x-5 above ...

    Text Solution

    |

  12. Find the largest natural number a for which the maximum value of f(x)=...

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |