1. The problem statement, all variables and given/known data Based only on differential equations, discuss why it is unlikely that d^2y/dt = ay with a > 0 has periodic solutions. 2. Relevant equations periodic functions go to infiniti or negative infiniti, differential equations are continuous... 3. The attempt at a solution so I said that the equation should be concave. the equation should be differentialble everywhere and has to be continuous with infinitely many inflection points. my teacher said that i'm on the right track but i need help putting my proof into words. any help?