Question

How do you do this? I am really confused

Answer 1

Explanation:

ok, so this is an infinitly repeating function, so you can write it as:

sqrt(12-x)

Although, x is also equal to sqrt(12-x), so

x = sqrt(12-x), and

x^2 = 12-x

x^2-12+x = 0

now just apply the quadratic formula and you're good

hope i helped :D