Home
Class 12
MATHS
Sachin and Rahul attempted to solve a qu...

Sachin and Rahul attempted to solve a quadratic equation. Sachin made a mistake in writing down the constant term and ended up in roots (4,3). Rahul made a mistake in writing down coefficient of x to get roots (3, 2). The correct roots of equation are:

A

`-4,-3`

B

`6,1`

C

`4,3`

D

`-6,-1`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem step by step, we need to analyze the information given about the roots obtained by Sachin and Rahul, and then derive the correct roots of the original quadratic equation. ### Step 1: Understand the roots obtained by Sachin and Rahul - Sachin obtained roots \(4\) and \(3\). - Rahul obtained roots \(3\) and \(2\). ### Step 2: Calculate the sum and product of the roots for both cases - For Sachin: - Sum of roots \(S_S = 4 + 3 = 7\) - Product of roots \(P_S = 4 \times 3 = 12\) - For Rahul: - Sum of roots \(S_R = 3 + 2 = 5\) - Product of roots \(P_R = 3 \times 2 = 6\) ### Step 3: Set up the equations based on the roots The general form of a quadratic equation based on its roots \(r_1\) and \(r_2\) is: \[ x^2 - (r_1 + r_2)x + (r_1 \cdot r_2) = 0 \] For Sachin's case: \[ x^2 - S_S x + P_S = 0 \implies x^2 - 7x + 12 = 0 \] For Rahul's case: \[ x^2 - S_R x + P_R = 0 \implies x^2 - 5x + 6 = 0 \] ### Step 4: Analyze the mistakes - Sachin made a mistake in the constant term, so the sum of the roots is correct, but the product is wrong. - Rahul made a mistake in the coefficient of \(x\), so the product of the roots is correct, but the sum is wrong. ### Step 5: Find the correct sum and product From the analysis: - The correct sum of the roots is \(S = 7\) (from Sachin). - The correct product of the roots is \(P = 6\) (from Rahul). ### Step 6: Form the correct quadratic equation Using the correct sum and product: \[ x^2 - Sx + P = 0 \implies x^2 - 7x + 6 = 0 \] ### Step 7: Factor the quadratic equation To factor \(x^2 - 7x + 6\): \[ x^2 - 7x + 6 = (x - 6)(x - 1) = 0 \] ### Step 8: Solve for the roots Setting each factor to zero gives: - \(x - 6 = 0 \implies x = 6\) - \(x - 1 = 0 \implies x = 1\) ### Final Answer The correct roots of the quadratic equation are \(1\) and \(6\). ---

To solve the problem step by step, we need to analyze the information given about the roots obtained by Sachin and Rahul, and then derive the correct roots of the original quadratic equation. ### Step 1: Understand the roots obtained by Sachin and Rahul - Sachin obtained roots \(4\) and \(3\). - Rahul obtained roots \(3\) and \(2\). ### Step 2: Calculate the sum and product of the roots for both cases - For Sachin: ...
Promotional Banner

Topper's Solved these Questions

  • THEORY OF EQUATIONS

    ARIHANT MATHS ENGLISH|Exercise Exercise (Subjective Type Questions)|24 Videos
  • THE STRAIGHT LINES

    ARIHANT MATHS ENGLISH|Exercise Exercise (Questions Asked In Previous 13 Years Exam)|17 Videos
  • THREE DIMENSIONAL COORDINATE SYSTEM

    ARIHANT MATHS ENGLISH|Exercise Three Dimensional Coordinate System Exercise 12 : Question Asked in Previous Years Exam|2 Videos

Similar Questions

Explore conceptually related problems

In solving quadratic equation x^(2) + px + q = 0 , one student makes mistake only in the constant term obtains 4 and 3 as the roots. Another students makes a mistake only in the coefficient of x and finds - 5 and - 2 as the roots. Determine the correct equation

Q. Two students while solving a quadratic equation in x, one copied the constant term incorrectly and got the roots as 3 and 2. The other copied the constant term and coefficient of x^2 as -6 and 1 respectively. The correct roots are :

The quadratic equation whose one root is (-3+ i sqrt7)/(4) is

The quadratic equation with rational coefficients whose one root is 3+sqrt2 is

Two candidates attempt to solve a quadratic equation of the form x^(2)+px+q=0 . One starts with a wrong value of p and finds the roots to be 2 and 6. the other starts with a wrong vlaue of q and finds the roots to be 2 and -9. find the correct roots and the equation.

Form a quadratic equation with real coefficients whose one root is 3-2idot

Find the nature of roots of the quadratic equation 4x^(2)-5x+3=0 .

ARIHANT MATHS ENGLISH-THEORY OF EQUATIONS-Exercise (Questions Asked In Previous 13 Years Exam)
  1. The smallest value of k, for which both the roots of the equation, x^2...

    Text Solution

    |

  2. If the roots of the equation b x^2+""c x""+""a""=""0 be imaginary, t...

    Text Solution

    |

  3. Let p and q real number such that p!= 0,p^3!=q and p^3!=-q. if alpha a...

    Text Solution

    |

  4. solve 0=1+2x+3x^2

    Text Solution

    |

  5. Find the roots of x^2-6x-2=0

    Text Solution

    |

  6. The value of b for which the equation x^2+bx-1=0 and x^2+x+b=0 have on...

    Text Solution

    |

  7. The roots of the equation 12 x^2 + x - 1 = 0 is :

    Text Solution

    |

  8. Let for a != a1 != 0 , f(x)=ax^2+bx+c ,g(x)=a1x^2+b1x+c1 and p(x) = f(...

    Text Solution

    |

  9. Sachin and Rahul attempted to solve a quadratic equation. Sachin made ...

    Text Solution

    |

  10. Let alpha(a) and beta(a) be the roots of the equation ((1+a)^(1/3)-1)x...

    Text Solution

    |

  11. Find the roots of x^2+7x+12=0

    Text Solution

    |

  12. If the equation x^2+2x+3=0 and ax^2+bx+c=0 have a common root then a:...

    Text Solution

    |

  13. Solve x^2+3x+9=0

    Text Solution

    |

  14. Let alpha and beta be the roots of equation px^(2) + qx + r = 0 , ...

    Text Solution

    |

  15. Let a in R and f : R rarr R be given by f(x)=x^(5)-5x+a, then (a) f...

    Text Solution

    |

  16. Solve x^2+3x+5=0

    Text Solution

    |

  17. Let S be the set of all non-zero real numbers such that the quadratic ...

    Text Solution

    |

  18. Find the sum of all real values of X satisfying the equation (x^2-5x+5...

    Text Solution

    |

  19. Let -pi/6 < theta < -pi/12. Suppose alpha1 and beta1, are the roots of...

    Text Solution

    |

  20. If, for a positive integer n , the quadratic equation, x(x+1)+(x-1)(x+...

    Text Solution

    |