## careless850 3 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. careless850

2. apoorvk

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

3. careless850

Yes.

4. careless850

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. careless850

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

7. careless850

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

8. careless850

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

9. careless850

So it would be

10. careless850

Step 3?

11. careless850

STEP 2!!!

12. careless850

13. apoorvk

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

14. careless850

No, it'd be -6.

15. careless850

-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. careless850

So, it's step 2, right?

19. apoorvk

Yup!

20. careless850

I have one more question.

21. apoorvk

22. apoorvk

Sure, just post it as a new one!

23. careless850

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