X^4 - x^2 + 9 - (x^3 + 3x^2 + 12) =
x^4 - x^3 - 4x^2 - 3
So we want to know which of the following functions has an inverse function. So an inverse function is a function that "reverses" another function. We need to put y instead of x and x instead of y. So for the first case: y=x is x=y so this function has an inverse function. y=x^2 is x=y^2 so y=sqrt(x). y=x^3 is x=y^3 so y=∛x. y=x^4 so x=y^4, y=4√x or forth root of x. So all of our functions have an inverse function.
All of the above are true
Perhaps you could just outline the topic lightly but try your best not to give away your topic idea. In this case talk about technology but don't talk about the dependency of technology, for the first paragraph as mentioned in your title text and then in your second paragraph you could talk about the dependency of technology.
