## anonymous one year ago Quadratics

1. anonymous

2x^2 - x + 1=0

2. welshfella

you need to solve this?

3. anonymous

yeah

4. anonymous

is there a formula or do i just work it out to find x

5. welshfella

well first thing is it won't factor so you need to use the quadratic formula and complete the square

6. welshfella

quadratic formula is x =[ -b +/- sqrt(b^2 - 4ac)] / 2a

7. anonymous

i got 0.91 and -0.41

8. anonymous

is that correct?

9. SolomonZelman

$$\large\color{black}{ \displaystyle 2x^2-x+1 =0 }$$ I am assuming you aren't planning to complete the square for this one (it's possible but is probably the hardest method here). So either factoring or quadratic formula. lets find the descriminant first. $$\large\color{black}{ \displaystyle \sqrt{(-1)^2 -4\cdot 2 \cdot 1 } =\sqrt{1-8}=\sqrt{-7}}$$

10. SolomonZelman

your solutions are imaginary (no real solutions)

11. anonymous

so they are wrong?

12. SolomonZelman

13. SolomonZelman

let me ask you, have you previously learned about $$i=\sqrt{-1}$$ ?

14. anonymous

no

15. SolomonZelman

so then (for you) it is no solution.