Question

Between x = 2 and x = 3, which function has a greater average rate of change than y = 13 -x ?

Answer 1

For this case what you should know is that the slope of the line can be calculated as:
 Tan x = sin x / cos x
 The lines x = 2 and x = 3 have an angle of 90 degrees with respect to the x axis:
 Tan 90 = sin 90 / cos 90 = 1/0 = inf
 Therefore, both lines have a rate of change that tends to infinity.
 answer
 Both lines have the same slope (infinity) Both are greater than m = -1