Verified Solution • 2025–26 Session moderate

QJEEM23Ma8be3: JEE Main 2023 Mathematics - Class 11 JEEM23Ma8be3 Solution: Let and then and are roots of the equation.

Let p,q∈R\mathrm{p,q\in\mathbb{R}} and (1−3i)200=2199(p+iq),i=−1{\left( {1 - \sqrt 3 i} \right)^{200}} = {2^{199}}(p + iq),i = \sqrt { - 1} then p+q+q2\mathrm{p+q+q^2} and p−q+q2\mathrm{p-q+q^2} are roots of the equation.

Multiple Choice Options

  • A x2+4x−1=0{x^2} + 4x - 1 = 0
  • B x2−4x+1=0{x^2} - 4x + 1 = 0
  • C x2+4x+1=0{x^2} + 4x + 1 = 0
  • D x2−4x−1=0{x^2} - 4x - 1 = 0

Step-by-Step Verified Solution

(1−3i)200{\left( {1 - \sqrt 3 i} \right)^{200}}

=[2(12−32i)]200= {\left[ {2\left( {{1 \over 2} - {{\sqrt 3 } \over 2}i} \right)} \right]^{200}}

=2200(cos⁡π3−isin⁡π3)200= {2^{200}}{\left( {\cos {\pi \over 3} - i\sin {\pi \over 3}} \right)^{200}}

=2200(cos⁡200π3−isin⁡200π3)= {2^{200}}\left( {\cos {{200\pi } \over 3} - i\sin {{200\pi } \over 3}} \right)

=2200(cos⁡(66π+2π3)−isin⁡(66θ+2π3))= {2^{200}}\left( {\cos \left( {66\pi + {{2\pi } \over 3}} \right) - i\sin \left( {66\theta + {{2\pi } \over 3}} \right)} \right)

=2200(cos⁡2π3−isin⁡2π3)= {2^{200}}\left( {\cos {{2\pi } \over 3} - i\sin {{2\pi } \over 3}} \right)

=2200(−12−32i)= {2^{200}}\left( { - {1 \over 2} - {{\sqrt 3 } \over 2}i} \right)

=2199(−1−3i)= {2^{199}}\left( { - 1 - \sqrt 3 i} \right)

=2199(p+iq)= {2^{199}}\left( {p + iq} \right)

∴\therefore p = −- 1 and q = −3- \sqrt3

Now, p−q+q2=−1+3+3=2+3=αp - q + {q^2} = - 1 + \sqrt 3 + 3 = 2 + \sqrt 3 = \alpha

and p+q+q2=−1−3+3=2−3=βp + q + {q^2} = - 1 - \sqrt 3 + 3 = 2 - \sqrt 3 = \beta

∴\therefore α+β=4\alpha + \beta = 4

αβ=(2+3)(2−3)=4−3=1\alpha \beta = \left( {2 + \sqrt 3 } \right)\left( {2 - \sqrt 3 } \right) = 4 - 3 = 1

∴\therefore Quadratic equation is

x2−(α+β)x+αβ=0{x^2} - (\alpha + \beta )x + \alpha \beta = 0

⇒x2−4x+1=0\Rightarrow {x^2} - 4x + 1 = 0

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