2. An aluminum bar must be heated before it can be properly worked. The bar is placed in a preheated oven, and its temperature A, in degrees Fahrenheit, after t minutes, is given by
A = 850 - 740e$^{-0.06t}$
a) Draw a graph of A versus t for the first 30 minutes the bar is in the oven.
b) Is the graph of A concave up or concave down? Explain in practical terms what this says about the temperature of the aluminum bar.
c) The aluminum bar will be ready for bending and shaping when it reaches 600°F. If you are asked to find how long it should remain in the oven, are you given the variable value or the function value?
d) Express using function notation the temperature of the aluminum bar after 14 minutes. Are you given the variable value or the function value?
e) How hot is the oven from part d?