The problem statement, all variables and given/known data How can I show that h(x)=[g(x)]^2 is concave upward on an interval if we know that g is positive and is concave upward on the same interval? The attempt at a solution I know that that g''(x)>0 since it concaves up. But after this step, I'm lost on proving this question. Any suggestions on how I should approach this question?? Thanks in advance!