Let f(t) be the weight (in grams) of a solid sitting in a beaker of water after t minutes have elapsed. Suppose that the solid dissolves in such a way that the rate of change (in grams/minute) of the weight of the solid at any time t can be determined from the weight using the forumula: f'(t)=-4f(t)(1+f(t))

If there is 5 grams of solid at time t=2 estimate the amount of solid 1 second later.