PLease Help!!
Find the complex solutions of the quadratic equation: 3(x^2)+2x+18=0

Question

PLease Help!!
Find the complex solutions of the quadratic equation: 3(x^2)+2x+18=0

campbell_st · Answer

ok... so you will need the general quadratic formula

$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$

now 

in your question 

a = 3, b = 2 and c = 18

you'll need to substitute them 

and then evaluate to get the complex solutions... it may be possible to simplify the solutions.

anonymous · Answer

I tried that and we supposed to use an imaginary number i .
I ve entered my answer 3 times but I still get it wrong, it is an online website for homework problems.

campbell_st · Answer

yes... you'll get to that... what did you get when you substituted.... and evaluated...

anonymous · Answer

i got for the final answer:
(-1+2(sqrt53)i)/3  and (-1-2(sqrt53)i)/3

campbell_st · Answer

so its 

$$x = \frac{ -2 \pm \sqrt{-212}}{6}$$

now 

$$i^2 = -1$$

so you will have 

$$x = \frac{-2 \pm \sqrt{212i^2}}{6}$$

campbell_st · Answer

so this will simplify to 

$$x = \frac{-1 \pm i \sqrt{53}}{3}$$

hope this makes sense

anonymous · Answer

Thanks, the website finally accepted the answer.

campbell_st · Answer

glad to help