dr silas studies a culture of bacteria under a microscope. the function b1(t)=1200(1.8)t represents the number of bacteria t hours after dr silas begins her study. (a) what does the value 1200 represent in this situation? (b) what does the value 1.8 represent in this situation? (c) the number of bacteria in a second study is modeled by the function b2(t)=1000(1.8)t. what does the value 1000 represent in this situation? what does the difference of 1200 and 1000 mean between the two studies?