Home
Class 11
MATHS
If a ne b and a^(2)=5a-3,b^(2)=5b-3, the...

If `a ne b and a^(2)=5a-3,b^(2)=5b-3`, then form that equation whose roots are `a/b and b/a`.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the quadratic equation whose roots are \( \frac{a}{b} \) and \( \frac{b}{a} \) given the equations \( a^2 = 5a - 3 \) and \( b^2 = 5b - 3 \). ### Step-by-Step Solution: 1. **Write down the equations**: We have two equations: \[ a^2 = 5a - 3 \quad \text{(1)} \] \[ b^2 = 5b - 3 \quad \text{(2)} \] 2. **Subtract the two equations**: Subtract equation (2) from equation (1): \[ a^2 - b^2 = (5a - 3) - (5b - 3) \] Simplifying this gives: \[ a^2 - b^2 = 5a - 5b \] We can factor the left-hand side: \[ (a - b)(a + b) = 5(a - b) \] Since \( a \neq b \), we can divide both sides by \( a - b \): \[ a + b = 5 \quad \text{(3)} \] 3. **Add the two equations**: Now, add equations (1) and (2): \[ a^2 + b^2 = (5a - 3) + (5b - 3) \] This simplifies to: \[ a^2 + b^2 = 5a + 5b - 6 \] Using equation (3), substitute \( a + b = 5 \): \[ a^2 + b^2 = 5(5) - 6 = 25 - 6 = 19 \quad \text{(4)} \] 4. **Calculate \( ab \)**: We can use the identity \( (a + b)^2 = a^2 + b^2 + 2ab \): \[ 5^2 = 19 + 2ab \] This gives: \[ 25 = 19 + 2ab \] Rearranging gives: \[ 2ab = 25 - 19 = 6 \implies ab = 3 \quad \text{(5)} \] 5. **Form the quadratic equation**: The roots of the quadratic equation we want are \( \frac{a}{b} \) and \( \frac{b}{a} \). The sum of the roots is: \[ \frac{a}{b} + \frac{b}{a} = \frac{a^2 + b^2}{ab} = \frac{19}{3} \] The product of the roots is: \[ \frac{a}{b} \cdot \frac{b}{a} = 1 \] Therefore, the quadratic equation is: \[ x^2 - \left(\frac{19}{3}\right)x + 1 = 0 \] 6. **Clear the fraction**: To eliminate the fraction, multiply through by 3: \[ 3x^2 - 19x + 3 = 0 \] ### Final Answer: The required quadratic equation is: \[ 3x^2 - 19x + 3 = 0 \]
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • QUADRATIC EQUATIONS

    ICSE|Exercise EXERCISE 10 (d)|14 Videos
  • QUADRATIC EQUATIONS

    ICSE|Exercise EXERCISE 10 (e)|4 Videos
  • QUADRATIC EQUATIONS

    ICSE|Exercise EXERCISE 10 (b)|16 Videos
  • PROPERTIES OF TRIANGLE

    ICSE|Exercise EXERCISE 7|38 Videos
  • RELATION AND FUNCTIONS

    ICSE|Exercise MULTIPLE CHOICE QUESTIONS (Choose the correct answer from the given four options in questions)|32 Videos

Similar Questions

Explore conceptually related problems

If the area of the triangle formed by the points (2a,b), (a+b, 2b+a) and (2b, 2a) be Delta_(1) and the area of the triangle whose vertices are (a+b, a-b), (3b-a, b+3a) and (3a-b, 3b-a) be Delta_(2) , then the value of Delta_(2)//Delta_(1) is

If the area of the triangle formed by the points (2a ,b)(a+b ,2b+a), and (2b ,2a) is 2q units , then the area of the triangle whose vertices are (a+b ,a-b),(3b-a ,b+3a), and (3a-b ,3b-a) will be_____

Knowledge Check

  • If b=3-a and b ne a , then (a^(2)-b^(2))/(b-a)=

    A
    3
    B
    1
    C
    0
    D
    `-3`
  • If 5a+3b=35 and (a)/(b)=(2)/(3) , what is the value of a?

    A
    `(14)/(5)`
    B
    `(7)/(2)`
    C
    `5`
    D
    `7`
  • If 5a=6b+7 and a -b =3, what is the value of b/2 ?

    A
    2
    B
    4
    C
    `5.5`
    D
    11
  • Similar Questions

    Explore conceptually related problems

    If the area of the triangle formed by the points (2a ,b)(a+b ,2b+a), and (2b ,2a) is 2qdotu n i t s , then the area of the triangle whose vertices are (1+b ,a-b),(3b-a ,b+3a), and (3a-b ,3b-a) will be_____

    If the equation x^(2) - 3x + b = 0 and x^(3) - 4x^(2) + qx = 0 , where b ne 0, q ne 0 have one common root and the second equation has two equal roots, then find the value of (q + b) .

    If A={1,2} and B={2,3} , then show that: AxxB ne B xxA

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

    If a^(3)-3a^(2)+5a-17=0 and b^(3)-3b^(2)+5b+11=0 are such that a+b is a real number, then the value of a+b is