## anonymous one year ago I need to find the zeroes of f(x) = 5x2 + 2x + 1

1. anonymous

@AliceCullen @ramseysa @Elsa213 @DaBest21 @thomaster

2. BloomLocke367

zeroes are just your solutions. It's where x=0, or where the graph crosses the x-axis. Do you know how to solve quadratics?

3. anonymous

No @BloomLocke367

4. BloomLocke367

Here, take a look at this tutorial to see if you understand. If you still need help, please do tag me and I'll try my best to help you! http://openstudy.com/users/bloomlocke367#/updates/55acffcee4b071e6530c96ce

5. anonymous

Wait, is -1/5 and 4/5

6. anonymous

Are those the zeroes?

7. BloomLocke367

Actually, I'm pretty sure the zeroes are complex roots. One moment. I have to double check my work.

8. anonymous

- 1/5 and - 4/5

9. BloomLocke367

No, those are not the roots. They are, in fact, complex. Do you know what a complex number is?

10. anonymous

No

11. anonymous

- 1/5 and - 2i/5

12. BloomLocke367

Basically, a complex number is a number that has an imaginary number in it. The often have a coefficient, i, and a constant. Here's an example of what it would look like: 3i+8. That's just an example, not the answer. Do you understand imaginary numbers? Where did you get those answers?

13. anonymous

Mathway, I suck at math and despise it. I'm sorry, I'm a history and English guy.

14. anonymous

Actually, I got them from Wolfram/Alpha

15. BloomLocke367

Really? huh. Try using the quadratic formula, which is $$\LARGE x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$$

16. BloomLocke367

In this case, a is 5, b is 2, and c is 1.

17. anonymous

(-2±√(2^2-4*5*1))/(2*5)

18. anonymous

Is it 1/10(-2 ± 4i)?

19. anonymous