Lake Mead in Nevada provides important ecosystem services including irrigation for agriculture, habitat for biodiversity, and recreation. Repeated droughts in the south west have lead to precipitous drops in the water level of the lake as shown in blue in the figure below. Fitting the water level with an exponential function the water level in year t is approximately given by: W(t) = 1080 +127e-0.161t Water Level (ft) 1200 1150 1100 0 5 10 Years since 2000 15 20 A. Use derivatives to calculate the rate of water level drop (in ft/year) in the year 2010 and the year 2020. B. Tangent lines can be a useful tool in formulating climate change projections. Find the equation or the tangent line to the W (t) at t = 20 (i.e. in the year 2020). Sketch this tangent line on the plot above. C. Use the tangent line you found in part B to make a projection for the water level in the lake in the year 2030.