## anonymous 4 years ago Harry is trying to solve the equation y = 2x^2 − x − 6 using the quadratic formula. He has made an error in one of the steps below. Find the step where Harry went wrong.

1. anonymous

2. apoorvk

First of all, do you know what the quadratic formula is?

3. anonymous

Yes.

4. anonymous

I wrote this problem out 6 times, still can't see WHERE he went wrong.

5. apoorvk

What are you corresponding 'a', 'b' and 'c' for this quadratic when you compare it with the standard equation of a quadratic "ax^2 + bx +c=0"?

6. anonymous

A = 2. B = -1. C = -6.

7. anonymous

$1 \pm \sqrt{-1^{2}} - 4*2*-6$

8. anonymous

-12 * -4 = 48. 1*1 = 1. $1 \pm \sqrt{1-48 } \div 2$

9. anonymous

So it would be

10. anonymous

Step 3?

11. anonymous

STEP 2!!!

12. anonymous

13. apoorvk

Should be : $x = \frac{-(-1) \pm \sqrt{(-1)^2 - 4 \times 3 \times (-6) }{} }{2\times 2 }$

14. anonymous

No, it'd be -6.

15. anonymous

-4 * 2 * -6.

16. apoorvk

actually the second step itself ha the error. (-1)^2 = 1 and yes that would be -4*2*-6 --> typo my bad.

17. apoorvk

*has

18. anonymous

So, it's step 2, right?

19. apoorvk

Yup!

20. anonymous

I have one more question.

21. apoorvk

22. apoorvk

Sure, just post it as a new one!

23. anonymous

Oh wow, I didn't realize I was in biology