If $\alpha , \beta $ are the roots of the equation $x^2 - 2x + 4 = 0$ , then the value of $\alpha ^n +\beta ^n$ is

  • A

    ${2^n}\cos \left( {\frac{{n\pi }}{3}} \right)$

  • B

    ${2^{n + 1}}\cos \left( {\frac{{n\pi }}{3}} \right)$

  • C

    ${2^n}\sin \left( {\frac{{n\pi }}{3}} \right)$

  • D

    ${2^{n + 1}}\sin \left( {\frac{{n\pi }}{3}} \right)$

Similar Questions

The sum of the roots of the equation, ${x^2}\, + \,\left| {2x - 3} \right|\, - \,4\, = \,0,$ is

  • [JEE MAIN 2014]

The number of distinct real roots of the equation $x^{5}\left(x^{3}-x^{2}-x+1\right)+x\left(3 x^{3}-4 x^{2}-2 x+4\right)-1=0$ is

  • [JEE MAIN 2022]

If the roots of ${x^2} + x + a = 0$exceed $a$, then

If $a,b,c$ are distinct real numbers  and $a^3 + b^3 + c^3 = 3abc$ , then the equation $ax^2 + bx + c = 0$ has two roots, out of which one root is

In a cubic equation coefficient of $x^2$ is zero and remaining coefficient are real has one root $\alpha = 3 + 4\, i$ and remaining roots are $\beta$ and $\gamma$ then $\alpha \beta \gamma$ is :-