1) Calculate the integrals
a) integral of (x^3/2 -5x)/(sqrt(x))
b) integral of ((x^3 +x)^10 * (3x^2+1))
2) Starting with 500 bacteria ,a colony grows with a rate proportionnal to its total . It has 800 bacteria after 3 hours
a) Determine the expression that gives the number of bacteria in function of time
b) What is the number of bacteria after 4 hours?
c) How much time is necessary for having 30 000 bacteria?