Beth purchased a computer, and its value depreciated exponentially each year. Beth will sketch a graph of the situation, where x
represents the number of years since she purchased the computer, and y represents its value that year. Beth will only sketch the graph in the quadrant or quadrants for which it makes sense to. In which quadrant or quadrants will Beth sketch the graph?
It is the number of years since purchase. Can this be negative?
NO! Years cannot be negative. So we disregard negative x-axis.
What is y?
It is the value of the computer at that year. A computer starts off with a positive value (y axis) and depreciates to 0 after some years. Can this be negative?
NO! At 0 value, the computer is worth nothing! There is nothing known as <em>negative </em>value. So we disregard negative y-axis.
The graph that Beth will sketch will have to be in the 1st quadrant (positive x-axis & positive y-axis).
