Question

can someone explain to me why the domain of x^2/(x^2+4) is not x cant be 2 or -2. my book says its all real number but how

Answer 1

Solve \(x^2+4=0\) and you will see why.

Answer 2

Remember that you can't divide by 0

Answer 3

maybe there is a typo in your question the function whose domain is all reals except 2 and -2 would have a - 4 in the denominator not + 4

Answer 4

@

Answer 5

@

Answer 6

@

Answer 7

The domain is all real number because denominator \(x^2+4\) cannot be 0 for any real number.

Answer 8

is it because i cant take the square root of the negative number?!

Answer 9

well, technically you can, but then you will be dealing with complex number.

Answer 10

but x^2 + 4 cannot be 0 for any real number because x^2 cannot = -4 for any real
that's why I said the denomiantor ought to be x^2 - 4

Answer 11

yes that what i meant i cant square root of -4 because then its not a real number

Answer 12

"my book says its all real number but how"

I don't think OP made mistake with denominator. @welshfella

Answer 13

Oh I see - I misread the question sorry
the domain is all real of course

Answer 14

yeah, I guess you could say that @eggshell

Answer 15

Thank You!