Question

he range of the function f(k) = k2 + 2k + 1 is {25, 64}. What is the function’s domain?
{5, 8}
{-5, -8}
{3, 8}
{4, 7}
{4, 8}

Answer 1

if 25 is in the range, that means the function outputs 25

ie f(k) = 25 for some values of k

Answer 2

you need to solve f(k) = 25 to find which values of k do this

same for f(k) = 64