The range of the function f (k) = k2 + 2k + 1 is {25, 64}. What is the function's domain?

Now if you understand the definition of range and domain it will be a lot simpler to answer.

Domain: The values that you can put into a function

Range: The values that the function spits out.

So the range here is from 25 to 64.

f (k) = k^2+2k+1, where f (k) is the range and k is the domain.

You will have to solve two equations for the boundary values, that is:

25=k^2+2k+1 and

64=k^2+2k+1

The function's domain are all of the "x" values or "k" values in this case that will satisfy the function's range. Hence, you should solve for k after that to get the function's domain after substituting for the function's range.