Problem 2.1: The point (0,0) lies on the graphs of which functions? [Solution]

Problem 2.2: The point (0,1) lies on the graphs of which functions? [Solution]

Problem 2.3: Which functions have a range of -1 to 1? [Solution]

Problem 2.4: Which functions approach ∞ and - ∞ as θ approaches zero? [Solution]

Problem 2.5: For which functions are the values between -1 and 1 not in the range? [Solution]