Question

find the domain of the function given by:
f(x)=2x
---
x^-4

Answer 1

You can see that x cannot be 0 because the fraction (and therefore function) would be undefined. Therefore the domain would be \(\mathbb{R} \setminus \{0\}\)

Answer 2

you could rewrite this as f(x) = 2x^5 since the exponent in denominator is negative.
In this case your domain is all real numbers

Answer 3

Oh, bah. Didn't see the negative sign.. Need to get my eyes checked ;p