Let f be the linear function (in blue) and let g be the parabolic function (in red) below. I have already tried 0,2,-1 and none of them work for the g o g(2) one and I'm soo confused. Please help!

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.