## anonymous 5 years ago x=-b+/- multipled by the square root of b squared - 4 ac

1. anonymous

yes?

2. myininaya

$x=\frac{-b \pm \sqrt{b^2-4ac}}{2a}$

3. anonymous

ok look my teacher gave us some equations and one of them are ${x}^2+6x+9=0$ and the answeres are x=-3 so i dont get it

4. anonymous

yes, this is (x+3)^2 so x = -3

5. anonymous

ok ;) so how do iget the answer for the first one

6. anonymous

Take the coefficient of the terms: i.e. the function is in ax^2+bx+c=0 form and plug the values of a, b, and c into the formula myiniaya posted, that is one way.

7. anonymous

which one is the first one?

8. anonymous

the first one is $x=-b \pm \sqrt{b ^{2}- 4ac} \div 2a$ ;D

9. myininaya

what do you want to solve for?

10. anonymous

11. myininaya

we can solve it for b, a, or c? its already solved for x

12. anonymous

that is the quadratic formula to find roots.

13. anonymous

well yeah the teacher wants us to find all thee a b and c but i dont reallly know how!

14. myininaya

she wants you to solve the quadratic formula for a then b then c are you sure?

15. anonymous

yes thats what she said :S

16. myininaya

k let's see if we can do it let's try to solve for a first

17. anonymous

ok ;D

18. anonymous

it is impossible to solve this equation for a b and c

19. myininaya

one sec

20. myininaya

i think you can use the quadratic formula to solve for a lol

21. anonymous

which is??

22. myininaya

23. anonymous

yes, but it impossible to solve for all three values of a,b and c

24. myininaya

lol. i honestly don't think this what your teacher wants

25. myininaya

i can solve for b and c use the quad on b and c is easiest

26. anonymous

no, you cannot. x can hold only two values. you need atleast 3 equations to solve for 3 unknown variables.

27. myininaya

a doeesnt have to be both it can be one or the other just like x

28. anonymous

you may be able to get a,b and c in terms of the other variables, but that doesn't get you any closer to solving for them.

29. myininaya

right but it sounded like he wanted us to solve the quadratic formula for each lol

30. anonymous

oh, that is just an exercise in stupidity.

31. anonymous

there is no point of that. I don't think their teacher asked them to solve for a,b and c.

32. myininaya

me neither