Question

please help me with problem anyone!
Solve x2 + 4x + 8 = 0.

Answer 1

in standard form a quadratic is written
ax^2+bx+c=0

You may know the quadratic formula.

However if the 'discriminant' of the equation is negative then there is no real solution.

The discriminant = b^2 - 4ac

Are you studying complex numbers? if so - the result is complex - if not - there is no real solution

Answer 2

yes i'm studying complex numbers

Answer 3

OK - then write the quadratic formula to get the solutions

You will end up with sqrt (-n) in the formula - so simplify that using

sqrt(-n) = i sqrt(n)

Answer 4

i got \[-4 \pm \sqrt{-16}\div2\]

Answer 5

x equals negative 2 plus or minus 4 I is this the answer

Answer 6

not quite - you need to divide the WHOLE by 2

Answer 7

x equals negative 2 plus or minus 4 I is this right?

Answer 8

\[x= \frac{-4\pm \sqrt{-16} }{2 }\]

not quite - you need to divide the WHOLE by 2

Answer 9

my answer choices are
x equals negative 2 plus or minus 2 I

x equals negative 2 plus or minus 4 I

x equals negative 4 plus or minus 2 I

x equals negative 4 plus or minus 4 I

Answer 10

so - you are nearly there - youtr first answer was wrong for the reason I told you.

Have another look at your arithmetic

Answer 11

that's confusing what

Answer 12

all I am saying is that you have done all the hard work - but you made a mistake with the division

Have another look at my formula and simplify it

Answer 13

would it be x equals negative 4 plus or minus 2 I

Answer 14

have confidence - is that correct?

Answer 15

I don't know...

Answer 16

\[\frac{ -4 }{ 2 }\pm \frac{ \sqrt{16} }{ 2 }\]

Answer 17

sorry - should be -16 above....

Answer 18

you have done all the work - and your answer IS correct.

But - you obviously understand quadratics and complex nos - so you should decide for yourself when you have the right answer...

Answer 19

so of the following answer choices which one is correct
x equals negative 2 plus or minus 2 I

x equals negative 2 plus or minus 4 I

x equals negative 4 plus or minus 2 I

x equals negative 4 plus or minus 4 I

Answer 20

you have done all the work - and your answer IS correct.

But - you obviously understand quadratics and complex nos - so you should decide for yourself when you have the right answer...