8. When an object with an initial temperature T is placed in a substance that has a temperature S, according to Newton's law of cooling, in t minutes it will reach a temperature T, using the formula T, = S+ (T-S) e, where k is a constant value that depends on properties of the object. For an initial temperature of 100 and k = 0.6, graphically display the resulting temperatures from 1 to 10 minutes for two different surrounding temperatures: 50 and 20. Use the plot function to plot two different lines for these surrounding temperatures, and store the handle in a variable. Notice that two function handles are actually returned, and stored in a vector. Use set to change the line width of one of the lines.