Home
Class 11
MATHS
If the roots of a1x^2 + b1x+ c1 = 0 ar...

If the roots of `a_1x^2 + b_1x+ c_1 = 0` are `alpha_1 ,beta_ 1` and those of `a_2x^2+b_2x+c_2=0` are `alpha_2,beta_2` such that `alpha_1alpha_2=beta_1beta_2=1` then

A

`(a_(1))/(a_(2))=(b_(1))/(b_(2))=(c_(1))/(c_(2))`

B

`(a_(1))/(c_(2))=(b_(1))/(b_(2))=(c_(1))/(a_(2))`

C

`a_(1) a_(2) = b_(1) b_(2) = c_(1) c_(2)`

D

none of these

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we will analyze the given quadratic equations and their roots step by step. ### Step 1: Identify the roots and their relationships We have two quadratic equations: 1. \( a_1x^2 + b_1x + c_1 = 0 \) with roots \( \alpha_1 \) and \( \beta_1 \) 2. \( a_2x^2 + b_2x + c_2 = 0 \) with roots \( \alpha_2 \) and \( \beta_2 \) From Vieta's formulas, we know: - For the first equation: - \( \alpha_1 + \beta_1 = -\frac{b_1}{a_1} \) (sum of roots) - \( \alpha_1 \beta_1 = \frac{c_1}{a_1} \) (product of roots) - For the second equation: - \( \alpha_2 + \beta_2 = -\frac{b_2}{a_2} \) (sum of roots) - \( \alpha_2 \beta_2 = \frac{c_2}{a_2} \) (product of roots) ### Step 2: Use the given conditions We are given: - \( \alpha_1 \alpha_2 = 1 \) - \( \beta_1 \beta_2 = 1 \) ### Step 3: Multiply the products of the roots Now, we can multiply the products of the roots: \[ \alpha_1 \beta_1 \cdot \alpha_2 \beta_2 = \left(\frac{c_1}{a_1}\right) \cdot \left(\frac{c_2}{a_2}\right) \] Substituting the values we have: \[ (\alpha_1 \alpha_2)(\beta_1 \beta_2) = 1 \cdot 1 = 1 \] Thus, \[ 1 = \frac{c_1 c_2}{a_1 a_2} \] Rearranging gives us: \[ c_1 c_2 = a_1 a_2 \] ### Step 4: Express relationships between coefficients Now, we can express relationships between the coefficients: From the previous step, we can also write: \[ \frac{c_1}{a_1} = \frac{a_2}{c_2} \] This gives us our first equation. ### Step 5: Find another relationship using sums of roots Next, we can find another relationship using the sums of the roots: \[ \alpha_1 \beta_1 (\alpha_2 + \beta_2) = \frac{c_1}{a_1} \left(-\frac{b_2}{a_2}\right) \] Substituting \( \alpha_1 \beta_1 = \frac{c_1}{a_1} \): \[ \frac{c_1}{a_1} (\alpha_2 + \beta_2) = \frac{c_1}{a_1} \left(-\frac{b_2}{a_2}\right) \] Cancelling \( \frac{c_1}{a_1} \) (assuming \( c_1 \neq 0 \)): \[ \alpha_2 + \beta_2 = -\frac{b_2}{a_2} \] ### Step 6: Final relationships From the relationships derived, we can summarize: 1. \( \frac{c_1}{a_1} = \frac{a_2}{c_2} \) 2. \( \frac{c_1}{a_2} = \frac{b_1}{b_2} \) Thus, we have established the relationships between the coefficients of the two quadratic equations.
Promotional Banner

Topper's Solved these Questions

  • QUADRATIC EXPRESSIONS AND EQUATIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Exercise|138 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 the roots of a_1x^(2)+b_1x+c_1=0 and alpha_1 , beta_1 and those of a_2x^(2)+b_2x+c_2=0 are alpha_2 , beta_2 such that alpha_1alpha_2=beta_1beta_2=1 then :

If alpha , beta are the roots of x^2 +x+1=0 then alpha beta + beta alpha =

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

If alpha , beta are the roots of ax^2+bx +c=0 then (1+ alpha + alpha ^2)(1+ beta + beta ^2) is

If alpha , beta are the roots of x^2-p(x+1)+c=0 then (1+alpha )( 1+ beta )=

If alpha , beta ,1 are roots of x^3 -2x^2 -5x +6=0 ( alpha gt 1) then 3 alpha + beta=

If alpha, beta and 1 are the roots of x^3-2x^2-5x+6=0 , then find alpha and beta

If alpha_1,alpha_2 are the roots of equation x ^2-p x+1=0a n dbeta_1,beta_2 are those of equation x^2-q x+1=0 and vector alpha_1 hat i+beta_1 hat j is parallel to alpha_2 hat i+beta_2 hat j , then p= a. +-q b. p=+-2q c. p=2q d. none of these

If w , w^(2) are the roots of x^(2)+x+1=0 and alpha, beta are the roots of x^(2)+px+q=0 then (w alpha+w^(2)beta)(w^(2)alpha+w beta) =

If alpha, beta are the roots of x^(2)+2x+5=0 , then the equation whose roots are (alpha+1)/(alpha), (beta+1)/(beta) is

OBJECTIVE RD SHARMA ENGLISH-QUADRATIC EXPRESSIONS AND EQUATIONS -Chapter Test
  1. If the equations ax^2+bx+c=0 and cx^2+bx+a=0, a!=c have a negative com...

    Text Solution

    |

  2. If the roots of the equation x^3-12x^2 +39x -28 =0 are in AP, then the...

    Text Solution

    |

  3. If the roots of a1x^2 + b1x+ c1 = 0 are alpha1 ,beta 1 and those o...

    Text Solution

    |

  4. If the roots of the equation ax^(2)-4x+a^(2)=0 are imaginery and the s...

    Text Solution

    |

  5. If a, b, c are positive real numbers, then the roots of the equation a...

    Text Solution

    |

  6. If the absolute value of the difference of the roots of the equation x...

    Text Solution

    |

  7. If alpha, beta be roots of the equation 375x ^(2) -25x-2=0 and s (n) =...

    Text Solution

    |

  8. The quadratic equation x^(2) + (a^(2) - 2) x - 2a^(2) and x^(2) - 3x +...

    Text Solution

    |

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

    Text Solution

    |

  10. The value of m for which the equation x^3-mx^2+3x-2=0 has two roots ...

    Text Solution

    |

  11. If the equation formed by decreasing each root of the a x^2+b x+c=0 by...

    Text Solution

    |

  12. If the roots of the equation ax^2-bx-c=0 are changed by same quantity ...

    Text Solution

    |

  13. If x^2-2rprx+r=0; r=1, 2,3 are three quadratic equations of which each...

    Text Solution

    |

  14. If x ^(2) + px +1 is a factor of ax ^(3) + bx +c, then:

    Text Solution

    |

  15. If (x-1)^3 is a factor of x^4+ax^3+bx^2+cx-1=0 then the other factor ...

    Text Solution

    |

  16. If alpha is a root of the equation x^2+2x-1=0, then prove that 4alpha^...

    Text Solution

    |

  17. If one root of the quadratic equation (a-b)x^2+ax+1=0 is double the ot...

    Text Solution

    |

  18. If the equation ax^(2) + bx + c = 0 and 2x^(2) + 3x + 4 = 0 have a co...

    Text Solution

    |

  19. If the equation x^(3) + ax^(2) + b = 0, b ne 0 has a root of order 2, ...

    Text Solution

    |

  20. If the roots of the equation x^(2) - bx + c = 0 are two consecutive in...

    Text Solution

    |