Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main20204 Sep 2020Morning ShiftMathematicsQuadratic EquationActual

Let α and β be the roots of x 2 - 3 x + p = 0 and γ and δ be the roots of x 2 - 6 x + q = 0 . If α , β , γ , δ from a geometric progression. Then ratio ( 2 q + p ) : ( 2 q - p ) is

Options

  1. A3 : 1
  2. B9 : 7
  3. C5 : 3
  4. D33 : 31

Correct answer

B. 9 : 7

Step-by-step solution

Let α = a ,   β = a r ,   γ = a r 2 ,   δ = a r 3 α + β = 3    ⇒ a + a r = 3 ........... 1 γ + δ = 6   ⇒ a r 2 + a r 3 = 6 ......... 2 By 1 and 2 ⇒   a r 2 1 + r a 1 + r = 6 3 ⇒   r 2 = 2 ∴ 2 q + p 2 q − p = 2 γ δ + α β 2 γ δ − α β = 2 a 2 r 5 + a 2 r 2 a 2 r 5 − a 2 r = 2 r 4 + 1 2 r 4 − 1 = 8 + 1 8 − 1 = 9 7

Practice Quadratic Equation on Quantrex Academy →

More from Quadratic Equation

Match each entry in List-I to the correct entry in List-II and choose the correct option. List-I List-II (P) If and are the distinct roots of the equation x^2 + x + 1 = 0 , then th 2026Let a, b, c be positive integers in arithmetic progression such that the equation ax^2 + bx + c = 0 has only integer solutions. Then which of the following statements is (are) TRUE 2026Consider the quadratic equation (n^2 - 2n + 2)x^2 - 3x + (n^2 - 2n + 2)^2 = 0 , n R . Let be the minimum value of the product of its roots and be the maximum value of the sum of it 2026Let one root of the quadratic equation in x : (k^2 - 15k + 27)x^2 + 9(k-1)x + 18 = 0 be twice the other. Then the length of the latus rectum of the parabola y^2 = 6kx is equal to: 2026Let e₁ and e₂ be two distinct roots of the equation x^2 - ax + 2 = 0 . Let the sets a R : e₁ and e₂ are the eccentricities of hyperbolas = ( , ) , and a R : e₁ and e₂ are the eccen 2026Let , be the roots of the equation x^2 - x + p = 0 and , be the roots the equation x^2 - 4x + q = 0 ; p, q Z . If , , , are in G.P., then |p + q| equals : 2026Let a, b C . Let , be the roots of the equation x^2 + ax + b = 0 . If - = 11 and ^2 - ^2 = 3i 11 , then ( ^3 - ^3)^2 is equal to: 2026Let A, B , where A, B (- 2 , 2 ) , be the roots of the quadratic equation x^2 - 2x - 5 = 0 . Then 20 ^2 ( A+B 2 ) is equal to: 2026 Full Quadratic Equation list All JEE Main PYQs