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JEE Main
Exam
JEE Main
Subject
Mathematics
Chapter
Basics of Mathematics

JEE Main · Mathematics · Basics of Mathematics

If α and β are the greatest divisors of n (n^ 2 - 1) and 2n (n^ 2 +...

If α\alpha and β\beta are the greatest divisors of n(n2−1)n \left(n^{2} - 1\right) and 2n(n2+2)2n \left(n^{2} + 2\right) respectively for all~n∈Nn \in N, then αβ=\alpha\beta =

Options

  1. A1818
  2. B3636
  3. C2727
  4. D99

Correct answer

B. 3636

Step-by-step solution

For n∈N⇒n=1,2,3…n \in N ⇒ n = 1, 2, 3 \ldots

The values of n(n2−1)n \left(n^{2} - 1\right) are

n=1⇒1(1−1)=0n = 1 ⇒ 1\left(1 - 1\right) = 0

n=2⇒2(4−1)=2(3)=6n = 2 ⇒ 2\left(4 - 1\right) = 2\left(3\right) = 6

n=3⇒3(9−1)=24…n = 3 ⇒ 3 \left(9 - 1\right) = 24 \ldots

The values of 2n(n2+2)2n\left(n^{2} + 2\right) are,

n=1⇒2(1+2)=6n = 1 ⇒ 2\left(1 + 2\right) = 6

n=2⇒2(2)(22+2)=4(6)=24n = 2 ⇒ 2\left(2\right)\left({2}^{2} +2\right) = 4\left(6\right) = 24

n = 3 ⇒ 2\left(3\right)\left({3}^{2} +2\right) = 6\left(11\right) = 66 \ldots</p><p></p><p>∴ Greatestdivisorsof αandβ areboth ~Greatest divisors of~\alpha and \beta~are both~6,</p><p>,</p><p>∴ \alpha\beta = \left(6\right)\left(6\right) = 36

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