The degree of a polynomial is the largest sum of the exponents of the terms. In this case, there is only one variable, so its simple: the largest exponent is 2, so this is a polynomial of degree 2, or a quadratic.

What happened to question ii)?

The notation indicates the inverse function. The inverse function has the property that, if then .

There's an algebraic method of finding these.

Let

Now exchange the roles of x and y:

Now solve for y:

Now we have that .

(Note: We really need to be a bit more careful than I was about domains and ranges. If you need more accuracy here, just let me know.)

-Dan