15 For a hot air balloon ride, the function H(t) gives
the height of the balloon after t minutes. Its graph
is shown alongside.
a Find H(30), and explain what your answer
means.
b Find the values of t such that Il(t) = 600.
Interpret your answer.
€ For what values of I was the height of the
balloon recorded?
d What range of heights was recorded for the
balloon?