11 A spoonful of sugar is dissolving in hot water. The initial mass of the sugar was 7 grams and 5 minutes later the mass present had halved. The mass of sugar, S grams, at time t minutes after it was placed in the hot water can be modelled by S(t) = S0e−kt, t ≥ 0. a State the value of S0. b Find the exact value of k. c Sketch the graph of S(t). d To the nearest second, how long after the sugar was placed in the hot water was its mass 1 gram? how do i graph part c on my calculator, which equation do i use to graph it?