edited by
339 views
2 votes
2 votes

A complex number $\alpha \in \mathbb{C}$ is called algebraic if there is a non-zero polynomial $P(x) \in \mathbb{Q}\left[x\right]$ with rational coefficients such that $P(\alpha)=0$. Which of the following statements is true?

  1. There are only finitely many algebraic numbers
  2. All complex numbers are algebraic
  3. $\sin (\frac{\pi}{3})+ \cos (\frac{\pi}{4}$) is algebraic
  4. None of the above
edited by

Please log in or register to answer this question.

Answer:

Related questions

2 votes
2 votes
1 answer
2
makhdoom ghaya asked Dec 21, 2015
508 views
Let $X \subset \mathbb{R}$ and let $f,g : X \rightarrow X$ be a continuous functions such that $f(X)\cap g(X)=\emptyset$ and $f(X)\cup g(X)= X$. Which one of the followin...
3 votes
3 votes
1 answer
4
makhdoom ghaya asked Dec 20, 2015
351 views
The series $\sum_{n=1}^{\infty}\frac{\cos (3^{n}x)}{2^{n}}$Diverges, for all rational $x \in \mathbb{R}$Diverges, for some irrational $x \in \mathbb{R}$Converges, for som...