Determine the number of real solutions of X^2 +5x + 8 = 0

Question

surana · Answer

The ^2 represents exponent 2 and the possible answers are 

A: 0
B: 1

surana · Answer

B is a double root, for notes.

surana · Answer

What I mean is that B's answer, 1, is a double root.

jhannybean · Answer

Use the discriminant, $b^2-4ac$

surana · Answer

How do I work that out?

fibonaccichick666 · Answer

Google the fundamental theorem of Algebra, you should find it interesting :)

anonymous · Answer

b is the value attached to the x variable, a is the one attached to the x^2 variable and c is the value attached to no variable.

surana · Answer

So that means B would be 5x and C would be 8?

fibonaccichick666 · Answer

^Value of the coefficients on those^^

anonymous · Answer

you could also use complete the square .

anonymous · Answer

No. b is 5 and c is 8.

jhannybean · Answer

$$b^2-4ac > 0 \implies 2~ \text{real solutions}$$$$b^2-4ac=0 \implies \text{1 real solution}$$$$b^2-4ac < 0 \implies \text{no real solutions}$$

surana · Answer

So I put 5 into B and 8 Into C?

anonymous · Answer

yes.

jhannybean · Answer

Know what your formula resembles. $$x^2+5x+8=0 \implies ax^2+bx+c=0$$

fibonaccichick666 · Answer

And let me just emphasize where that all comes from:  so, do you remember the quadratic formula?  The discriminant is what is inside the square root

surana · Answer

So it should look like 25 - 4a 8?

fibonaccichick666 · Answer

this is why we see if it is positive or negative

surana · Answer

But I think I need a number for a, right?

jhannybean · Answer

@Surana Can you identify what $$a=~?$$$$b=~?$$$$c=~?$$

surana · Answer

I think that A is supposed to be X^2.

jhannybean · Answer

Look at what I posted here and match up your formula with the quadratic. $$\color{red}{x^2+5x+8=0 \implies ax^2+bx+c=0}$$

surana · Answer

So I put 1 into the place of A, 5 into the place of B and 8 into the place of C?

jhannybean · Answer

So a b and c are called the coefficients of the variable terms. That is precisely what you are looking for to find the discriminant.

jhannybean · Answer

If nothing is in front of $x^2$ you can infer that the variable coefficient =1.

surana · Answer

Then I need to calculate for A, B and C, first.

surana · Answer

I see what you mean now, so the A number is 1, since there was nothing explicitly mentioned there, meaning my answer is B?