Solve dy da - sin r Y if y(0) = -2. A certain bacteria population increases continuously at a rate proportional to its current number. The initial population of the bacteria is 70. The population increases to 360 bacteria in 4 hours. Approximately how many bacteria are there in 7 hours? Round your answer to the nearest whole number. Use substitution to determine the approximate value of sin a Vo cos a da. Evaluate f z-3x+9 23+27 dr. Let dz /xy = 0 and y=0 when z = 1. If y = 73, what is the best approximation for x?