Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 20266 AprilEvening Shift
Exam
JEE Main
Year
2026
Date
6 April
Shift
Evening Shift
Subject
Mathematics
Chapter
Quadratic Equation

JEE Main 2026 · 6 April · Evening Shift · Mathematics · Quadratic Equation

Consider the quadratic equation (n^2 - 2n + 2)x^2 - 3x + (n^2 - 2n...

Consider the quadratic equation (n2−2n+2)x2−3x+(n2−2n+2)2=0(n^2 - 2n + 2)x^2 - 3x + (n^2 - 2n + 2)^2 = 0, n∈Rn \in \mathbb{R}. Let α\alpha be the minimum value of the product of its roots and β\beta be the maximum value of the sum of its roots. Then the sum of the first six terms of the G.P., whose first term is α\alpha and the common ratio is αβ\dfrac{\alpha}{\beta}, is :

Options

  1. A6137\dfrac{61}{37}
  2. B12181\dfrac{121}{81}
  3. C364243\dfrac{364}{243}
  4. D1093729\dfrac{1093}{729}

Correct answer

C. 364243\dfrac{364}{243}

Step-by-step solution

The given quadratic equation is (n2−2n+2)x2−3x+(n2−2n+2)2=0(n^2 - 2n + 2)x^2 - 3x + (n^2 - 2n + 2)^2 = 0.

Let k=n2−2n+2=(n−1)2+1k = n^2 - 2n + 2 = (n-1)^2 + 1. Since (n−1)2≥0(n-1)^2 \ge 0 for all n∈Rn \in \mathbb{R}, the minimum value of kk is 11 at n=1n=1.

The product of the roots is given by P=(n2−2n+2)2n2−2n+2=n2−2n+2=kP = \dfrac{(n^2 - 2n + 2)^2}{n^2 - 2n + 2} = n^2 - 2n + 2 = k.

The minimum value of the product of the roots is α=min⁡(k)=1\alpha = \min(k) = 1.

The sum of the roots is given by S=3n2−2n+2=3kS = \dfrac{3}{n^2 - 2n + 2} = \dfrac{3}{k}.

The maximum value of the sum of the roots occurs when kk is minimum. Thus, β=max⁡(3k)=31=3\beta = \max\left(\dfrac{3}{k}\right) = \dfrac{3}{1} = 3.

We are given a Geometric Progression (G.P.) whose first term is a=α=1a = \alpha = 1 and common ratio is r=αβ=13r = \dfrac{\alpha}{\beta} = \dfrac{1}{3}.

The sum of the first six terms of this G.P. is:

S6=a1−r61−r=1⋅1−(13)61−13S_6 = a \dfrac{1 - r^6}{1 - r} = 1 \cdot \dfrac{1 - \left(\dfrac{1}{3}\right)^6}{1 - \dfrac{1}{3}}

S6=1−172923=72872923S_6 = \dfrac{1 - \dfrac{1}{729}}{\dfrac{2}{3}} = \dfrac{\dfrac{728}{729}}{\dfrac{2}{3}}

S6=728729×32=364243S_6 = \dfrac{728}{729} \times \dfrac{3}{2} = \dfrac{364}{243}

Answer: 364243\dfrac{364}{243}
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.… JEE Advanced 2026Let a, b, c be positive integers in arithmetic progression such that the equation ax^2 +… JEE Advanced 2026Let one root of the quadratic equation in x : (k^2 - 15k + 27)x^2 + 9(k-1)x + 18 = 0 be… JEE Main 2026Let e_1 and e_2 be two distinct roots of the equation x^2 - ax + 2 = 0 . Let the sets \ a… JEE Main 2026Let α, β be the roots of the equation x^2 - x + p = 0 and γ, δ be the roots the equation… JEE Main 2026Let a, b ∈ ℂ . Let α, β be the roots of the equation x^2 + ax + b = 0 . If β - α = 11 and… JEE Main 2026Let A, B , where A, B ∈ (-(π)/(2), (π)/(2)) , be the roots of the quadratic equation x^2… JEE Main 2026If α=1 and β=1+i 2 , where i= -1 are two roots of the equation x^3+ax^2+bx+c=0 , a,b,c ∈… JEE Main 2026If the quadratic equation (λ+2)x^2-3λ x+4λ=0 , λ ≠ -2 , has two positive roots, then the… JEE Main 2026Let α, β be the roots of the equation x^2 - 3x + r = 0 , and (α)/(2), 2β be the roots of… JEE Main 2026Let a, b, c ∈ \ 1, 2, 3, 4\ . If the probability, that ax^2 + 2 2 \,bx + c > 0 for all x… JEE Main 2026Let S=\ x^ 3 +a x^ 2 +b x+c: a, b, c ∈ ~N. and .a, b, c ≤ 20\ be a set of polynomials.… JEE Main 2026If α, β , where α<β , are the roots of the equation λ x^ 2 -(λ+3) x+3=0 such that… JEE Main 2026The smallest positive integral value of a , for which all the roots of x^ 4 -a x^ 2 +9=0… JEE Main 2026The sum of all the real solutions of the equation _ (x+3) (6 x^ 2 +28 x+30)=5-2 _ (6… JEE Main 2026A building construction work can be completed by two masons A and B together in 22.5… JEE Main 2026 Full Quadratic Equation list Quadratic Equation JEE Maths PYQsJEE Mathematics PYQs All JEE Main PYQs