Home
Class 12
MATHS
If p and q are the roots of x^(2)+px +q=...

If p and q are the roots of `x^(2)+px +q=0`, the

A

p=1

B

p=1 or 0

C

p=-2

D

p=-2 or 0

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we start with the quadratic equation given: \[ x^2 + px + q = 0 \] where \( p \) and \( q \) are the roots of the equation. ### Step 1: Use Vieta's Formulas According to Vieta's formulas, for a quadratic equation of the form \( ax^2 + bx + c = 0 \): - The sum of the roots \( \alpha + \beta = -\frac{b}{a} \) - The product of the roots \( \alpha \beta = \frac{c}{a} \) In our case: - The roots are \( p \) and \( q \) - The coefficients are \( a = 1 \), \( b = p \), and \( c = q \) Thus, we can write: 1. \( p + q = -\frac{p}{1} = -p \) 2. \( pq = \frac{q}{1} = q \) ### Step 2: Rearranging the Equations From the first equation \( p + q = -p \), we can rearrange it: \[ p + q + p = 0 \] \[ 2p + q = 0 \] This gives us our first equation: \[ q = -2p \] (Equation 1) From the second equation \( pq = q \), we can rearrange it: \[ pq - q = 0 \] Factoring out \( q \): \[ q(p - 1) = 0 \] ### Step 3: Analyzing the Factors From the factored equation \( q(p - 1) = 0 \), we have two cases: 1. \( q = 0 \) 2. \( p - 1 = 0 \) which gives \( p = 1 \) ### Step 4: Case 1: If \( q = 0 \) If \( q = 0 \), substitute \( q \) back into Equation 1: \[ 0 = -2p \] This implies: \[ p = 0 \] ### Step 5: Case 2: If \( p = 1 \) If \( p = 1 \), substitute \( p \) back into Equation 1: \[ q = -2(1) = -2 \] ### Conclusion The possible values for \( p \) are: - From Case 1: \( p = 0 \) - From Case 2: \( p = 1 \) Thus, the values of \( p \) can be either \( 0 \) or \( 1 \). ### Final Answer The values of \( p \) are \( 0 \) and \( 1 \). ---
Promotional Banner

Topper's Solved these Questions

  • THEORY OF QUADRATIC EQUATIONS

    ML KHANNA|Exercise Problem Set - 1 (True And False)|3 Videos
  • THEORY OF QUADRATIC EQUATIONS

    ML KHANNA|Exercise Problem Set - 1 (Fill In The Blanks)|4 Videos
  • THE PARABOLA

    ML KHANNA|Exercise MISCELLANEOUS EXERCISE (Assertion/ Reason)|1 Videos
  • TRIGONOMETRICAL EQUATIONS

    ML KHANNA|Exercise SELF ASSESSMENT TEST |27 Videos

Similar Questions

Explore conceptually related problems

If k and 2k^(2) are the roots of x^(2)-px+q=0, then q+4q^(2)+6pq=

If x^(2)+px+q=0 is the quadratic equation whose roots are a-2 and b-2 where a and b are the roots of x^(2)-3x+1=0, then p-1,q=5 b.p=1,1=-5 c.p=-1,q=1 d.p=1,q=-1

If p, q are the roots of equation x^(2)+px+q=0, then value of p must be equal to

Let p and q are non-zeros.The equation x^(2)+px+q=0 has p and q as the roots.The roots of x^(2)+px+q=0 are

If a + b ne 0 and the roots of x^(2) - px + q = 0 differ by -1, then p^(2) - 4q equals :

If p and q are the root of the equation x^(2) - px + q = 0 , then what are the vlaues of p and q respectively ?

ML KHANNA-THEORY OF QUADRATIC EQUATIONS -Self Assessment Test
  1. If p and q are the roots of x^(2)+px +q=0, the

    Text Solution

    |

  2. If the equation x^(2)-(2+m)x +(m^(2)-4m+4)=0 has equal roots then the ...

    Text Solution

    |

  3. The number of real solutions of the equation |x|^(2)-3|x|+2=0 is :

    Text Solution

    |

  4. Find the number of solution of the equation e^(sinx)-e^(-sinx)-4=0

    Text Solution

    |

  5. The roots of the equation (p-q) x^(2)+(q-r) x+(r-p)=0 are

    Text Solution

    |

  6. If one root of x^(2) + px+12 = 0 is 4, while the equation x ^(2)...

    Text Solution

    |

  7. Let alpha and beta are the roots of the equation x^(2) + x + 1 = 0 The...

    Text Solution

    |

  8. If the quadratic equation x^(2) +ax +b =0 and x^(2) +bx +a =0 (a ne b...

    Text Solution

    |

  9. If the roots of the equation x^2-8x+a^2-6a=0 are real distinct, then f...

    Text Solution

    |

  10. The value of k for which the equation x^(2)-(3k-1)x+2k^(2)+2k=11 have ...

    Text Solution

    |

  11. if 2 = I sqrt3 be a root of the equation x^(2) + px + q =0, where p ...

    Text Solution

    |

  12. The number of solutions of the pair of equations 2s in^2theta-cos2thet...

    Text Solution

    |

  13. If alpha, beta are roots of the equations Ax^(2)+Bx+C=0. Then value of...

    Text Solution

    |

  14. If the equation x^(2)+px+q=0 and x^(2)+qx+p=0 have a common root then ...

    Text Solution

    |

  15. If alpha and beta (alpha lt beta) are the roots of the equation x^(2) ...

    Text Solution

    |

  16. If 2a+3b+6c=0, then prove that at least one root of the equation a x^2...

    Text Solution

    |

  17. If the roots of the equation (x^2-b x)/(a x-c)=(m-1)/(m+1) are equal t...

    Text Solution

    |

  18. If sin alpha, cos alpha are the roots of the equation ax^(2)+bx+c=0, t...

    Text Solution

    |

  19. If alpha, beta are the roots of x^(2)-ax+b =0 and If alpha^(n)+beta^(n...

    Text Solution

    |

  20. The value of a for which one root of the quadratic equation (a^2-5a+3)...

    Text Solution

    |

  21. If a,b, c are in G.P., then the equations ax^(2) + 2bx + c = 0 and dx^...

    Text Solution

    |