A biker traveling with a velocity of 80 feet per second leaves a 100 feet platform and is projected directly upward.  The function for the projectile motion  Is s(t) = -16t² +80t + 100  where s(t) is the height and t is the seconds the biker is in the air.

a)      Looking at your calculator, find the number of seconds the biker is in the air (or “hang time”).  Then find the range of height values that the biker attains.

b)      State the domain and range of this real life example.  Remember that time isn’t negative and that the model is valid only when the biker is in the air!

c)      Use the graph to determine when the biker will reach a height of 100 feet.  State the (these) point(s) as an order pair and using functional notation.

d)     Use the graph to determine what height the biker will attain after 1 second.  State the point as an ordered pair and using functional notation.

Where is the function increasing?  In other words, for what x-values does the biker continue to get higher?  Where is the function decreasing? In other words, for what x-values does the biker start descending toward the ground?  State these intervals using interval notation