1. The problem statement, all variables and given/known data I have a series of problems 1.problem. When this number is summed with its square. The summ is the least possible. 2.problem Find positive number which substraction with its third power would be the greatest. 3.problem Find to numbers which x+y=5 but multiplication is the least 2. Relevant equations 1)x+x^2= 2)x-x^3= 3)x+y=5, x*y= 3. The attempt at a solution I suppose I should you use limits but cant figure out how ( what kind of limit i should use) Some-kind of help ,please?