Home
Class 12
MATHS
If one root of the quadratic equation px...

If one root of the quadratic equation `px^2 +qx + r = 0 (p != 0)` is a surd `sqrta/(sqrta+sqrt(a-b),` where `p, q, r; a, b` are all rationals then the other root is -

A

`(sqrt(a))/(sqrt(a)- sqrt(a)-b)`

B

`(sqrt(a)-sqrt(a)-b)/(sqrt(b))`

C

`a+ sqrt(a(a-b))/(b)`

D

`(a+ sqrt(a(a-b)))/(b)`

Text Solution

Verified by Experts

The correct Answer is:
1,4

One root `(sqrt(a))/(sqrt(a)+sqrt(a)-b)`
On retionalizing , we get
`(sqrt(a))/(sqrt(a)+sqrt(a)-b)xx(sqrt(a)-sqrt((a)-b))/(sqrt(a)+sqrt((a)-b))`
`(sqrt(a) (.sqrt(a) - sqrt(a-b)))/(b)= (a - sqrt(a (a - b)))/(b)`
` therefore ` Other root = ` (a+sqrt((a-b)))/(b)`
Rationalizing , we get
` (a+sqrt((a-b)))/(b)xx(a - sqrt(a(a-b)))/(a - sqrt(a(a-b)))`
`(a^(2) - (a^(2) - ab))/(b(a- sqrt(a (a - b))))= (sqrt(a))/(sqrt(a)- sqrt(a-b))`.
Promotional Banner

Topper's Solved these Questions

  • THEORY OF EQUATIONS

    CENGAGE|Exercise Exercise (Comprehension)|37 Videos
  • THEORY OF EQUATIONS

    CENGAGE|Exercise Exercise (Matrix)|6 Videos
  • THEORY OF EQUATIONS

    CENGAGE|Exercise Exercise (Single)|89 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 one root of the quadratic equation px^(2)+qx+r=0(p!=0) is a surd (sqrt(a))/(sqrt(a)+sqrt(a-b)) where p,q,r;a,b are all rationals then the other root is -

If the roots of the equation x^(3) - px^(2) + qx - r = 0 are in A.P., then

If p,q,r in R and the quadratic equation px^(2)+qx+r=0 has no real root,then

If the roots of the equation px^(2)+qx+r=0 are in the ratio l:m then

If the roots of the quadratic equation px^(2)+qx+r=0 are reciprocal to each other ,then the relation between p and r is

If p,q,r are + ve and are in A.P., the roots of quadratic equation px^2 + qx + r = 0 are all real for

CENGAGE-THEORY OF EQUATIONS-Exercise (Multiple)
  1. if c!=0 and the equation p/(2x)=a/(x+c)+b/(x-c) has two equal roots, t...

    Text Solution

    |

  2. If alpha,beta are the roots of the quadratic equation a x^2+b x=c=0 , ...

    Text Solution

    |

  3. If one root of the quadratic equation px^2 +qx + r = 0 (p != 0) is a s...

    Text Solution

    |

  4. If a,b,c are in G.P. then the roots of the equation a x^2 + bx + c = 0...

    Text Solution

    |

  5. the roots of the equation (a+sqrt(b))^(x^2-15)+(a-sqrt(b))^(x^2-15)=2a...

    Text Solution

    |

  6. If the equation x^2+px+q=0 and x^2+p'x+q'=0 have a common root show th...

    Text Solution

    |

  7. If the quadratic equation a x^2+b x+c=0(a >0) has sec^2thetaa n dcos e...

    Text Solution

    |

  8. Given that alpha,gamma are roots of the equation A x^2-4x+1=0,a n dbet...

    Text Solution

    |

  9. If cos^4theta+alpha are the roots of the equation x^2+2b x+b=0a n dcos...

    Text Solution

    |

  10. If alpha,beta are the roots of the equation ax^2 + bx+c=0 then the roo...

    Text Solution

    |

  11. If every pair of equations x^2+ax+bc=0, x^2+bx+ca=0 and x^2+cx+ab=0 ha...

    Text Solution

    |

  12. If the equation 4x^2-x-1=0a n d3x^2+(lambda+mu)x+lambda-mu=0 have a ro...

    Text Solution

    |

  13. If x^3+3x^2-9x+c is of the form (x-alpha)^2(x-beta) then c is equal to

    Text Solution

    |

  14. If the equation whose roots are the squares of the roots of the cubic ...

    Text Solution

    |

  15. If f(x) is a polynomial of degree 4 with rational coefficients a...

    Text Solution

    |

  16. (x^3+1/x^3)-3(x^2+1/x^2)+6(x+1/x)-7=0

    Text Solution

    |

  17. 2x^2+6xy+5y^2=1, then

    Text Solution

    |

  18. If f(x) = ax^(2) + bc + c , where a ne 0, b ,c in R , then which ...

    Text Solution

    |

  19. If (x^(2) + 5)/(2) = x - 2 cos (m + nx) has at least one real root, ...

    Text Solution

    |

  20. Let three quadratic equations ax^(2) - 2bx + c = 0, bx^(2) - 2 cx + a...

    Text Solution

    |