I need an equation with a negative discriminant?

Question

anonymous · Answer

Okay, well, start with: $$
ax^2+bx+c
$$

anonymous · Answer

To make it simple, let $a=1$.$$
x^2+bx+c
$$We need $b^2-4c<0$.

anonymous · Answer

I just need an equation with a negative discriminant and then understand how to find the solutions, even though they are not real.

zzr0ck3r · Answer

note that if b = 1, then b^2 = 1

so we want 1-4c to be negative

what could we make c to assure 1-4c is negative?

anonymous · Answer

a positive number?

zzr0ck3r · Answer

not just positive, because 1/4 would not work

because 1-4*1/4 = 1-1=0 is not negative

try something else

zzr0ck3r · Answer

think bigger...

anonymous · Answer

2

zzr0ck3r · Answer

sure, 1-4*2 = 1-8 = -7

misty1212 · Answer

$$x^2+1=0$$

misty1212 · Answer

all you are looking for is a quadratic equation that has complex solutions 
that is the simplest one i know of

zzr0ck3r · Answer

so you have a=1, b=1, c = 2 and you are done

anonymous · Answer

and how do i solve this?

anonymous · Answer

its 1x^2+1x+2 right?

zzr0ck3r · Answer

you have x^2+x+2, this is all the question asks for.

what do you mean solve?

find the roots?

anonymous · Answer

and what did misty mean?

anonymous · Answer

yeah, the question says Create an equation with a negative discriminant. Then explain how to find the solutions, even though they are not real.

misty1212 · Answer

$$x^2+1=0\
x^2=-1\
x=\pm\sqrt{-1}\
x=\pm i$$

misty1212 · Answer

it is the simplest quadratic equation with complex solutions, so the discriminant must be negative

misty1212 · Answer

of course you are free to make up a much more complicated one
almost anything will do

anonymous · Answer

I get it now. thanks guys for all the help