a Find the point on the curve whose y-coordinate is 20.
B
b Find two points on the curve whose x-coordinates are 1 and 3.
A
a After 2 weeks
B
b Stock prices dropped $30
Practice makes perfect
a Looking at the given graph of the exponential function that represents a projection of stock prices, we can see that the point ( 2, 20) is on the curve.
This point means that after 2 weeks the stock will be worth $ 20.
b Now we are asked to determine the change in stock prices during a time period. Let's first find the stock prices after the first and third week.
We see that after a week the stock price is $40 and after three weeks it is $10. The change in the price is 30 between these weeks. Notice that this change is less than the change in the first week.
