Exercise 3.7.6 A data plan at an internet cafe' charges $1.00 for the rst minute and $0.50 for each additional minute or part thereof, subject to a maximum of $3.00. Derive a function f relating the data charges to the length of time it spent at the cafe. Sketch the graph off andr determine the values of x for which the function is discontinuous. Exercise 3.7.7 Approximate a root off : x3 4x2 + 2x+ 2 to one decimal place. Exercise 3.7.9 Show that the equation 3/} +x = 1 has a solution in the interval (0, 8)