JEE MAIN - Mathematics (2023 - 24th January Morning Shift - No. 1)
Explanation
$${\left( {1 - \sqrt 3 i} \right)^{200}}$$
$$ = {\left[ {2\left( {{1 \over 2} - {{\sqrt 3 } \over 2}i} \right)} \right]^{200}}$$
$$ = {2^{200}}{\left( {\cos {\pi \over 3} - i\sin {\pi \over 3}} \right)^{200}}$$
$$ = {2^{200}}\left( {\cos {{200\pi } \over 3} - i\sin {{200\pi } \over 3}} \right)$$
$$ = {2^{200}}\left( {\cos \left( {66\pi + {{2\pi } \over 3}} \right) - i\sin \left( {66\theta + {{2\pi } \over 3}} \right)} \right)$$
$$ = {2^{200}}\left( {\cos {{2\pi } \over 3} - i\sin {{2\pi } \over 3}} \right)$$
$$ = {2^{200}}\left( { - {1 \over 2} - {{\sqrt 3 } \over 2}i} \right)$$
$$ = {2^{199}}\left( { - 1 - \sqrt 3 i} \right)$$
$$ = {2^{199}}\left( {p + iq} \right)$$
$$\therefore$$ p = $$-$$1 and q = $$- \sqrt3$$
Now, $$p - q + {q^2} = - 1 + \sqrt 3 + 3 = 2 + \sqrt 3 = \alpha $$
and $$p + q + {q^2} = - 1 - \sqrt 3 + 3 = 2 - \sqrt 3 = \beta $$
$$\therefore$$ $$\alpha + \beta = 4$$
$$\alpha \beta = \left( {2 + \sqrt 3 } \right)\left( {2 - \sqrt 3 } \right) = 4 - 3 = 1$$
$$\therefore$$ Quadratic equation is
$${x^2} - (\alpha + \beta )x + \alpha \beta = 0$$
$$ \Rightarrow {x^2} - 4x + 1 = 0$$
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