Solve using the quadratic formula.
1. x^2 + x + 12
2. 4x^2 - 17x - 15 = 0

Question

Solve using the quadratic formula.
1. x^2 + x + 12
2. 4x^2 - 17x - 15 = 0

astrophysics · Answer

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

astrophysics · Answer

Where your expression is of the sort $$ax^2+by+c =0$$

amberlykhan · Answer

Im stumped. So far I got x = -1 +/- (square of -47) all divided by 2

amberlykhan · Answer

@Astrophysics

amberlykhan · Answer

what do i do now

astrophysics · Answer

$$x^2+x+12 \implies a=1,b =1, c = 12$$
$$x = \frac{ -1\pm \sqrt{1^2-4(1)(12)} }{ 2(1) } = \frac{ -1 \pm \sqrt{-47} }{ 2 }$$ this requires complex numbers, do you know them?

anonymous · Answer

stick to your guns 
it is right unless you want to  use $i$

astrophysics · Answer

$$x = \frac{ -1\pm \sqrt{1^2-4(1)(12)} }{ 2(1) } = \frac{ -1 \pm \sqrt{-47} }{ 2 } = \frac{ -1 \pm i \sqrt{47} }{ 2 }$$

astrophysics · Answer

This lag is insane

astrophysics · Answer

Hey, yeah do as satellite says if you don't know complex numbers leave it, I'm sure your teacher doesn't want you to use it, but in any case $$i = \sqrt{-1}$$

sbuck98 · Answer

Do you need anymore help?