## anonymous one year ago which one of the following is a complex zero of P(x)=x^4-16

1. anonymous

$x^4-16=(x^2+4)(x^2-4)=(x^2+4)(x+2)(x-2)$

2. anonymous

the real zeros are $$2$$ and $$-2$$

3. anonymous

the complex ones you get from solving $x^2+4=0$ do you know how to do that?

4. anonymous

wouldn't x=2?

5. anonymous

no

6. anonymous

$x^2+4=0\\ x^2=-2\\ x=\pm\sqrt{-2}$ or $x=\pm\sqrt{2}i$

7. anonymous

it is not $$x=2$$ because $$2^2+4=4+4=8$$ not zero

8. anonymous

okay so what if my choices are only..

9. anonymous

i made a typo there second line should be $$x^2=-4$$

10. anonymous

$$-2i$$ and $$2i$$ are the zeros pick $$-2i$$ who is jsara?

11. anonymous

okay that makes sense.... and i just typed in random letters but I asked myself that same question as i was sending it hahahaha

12. anonymous

if those letters are random i will have a beer now