Answer:
Step-by-step explanation:
A relative maximum (or minimum) point is a point that is higher (or lower) than all of the points surrounding it.
This graph has a relative minimum point where A(t)=-12A(t)=−12A, left parenthesis, t, right parenthesis, equals, minus, 12, which means that Keith's lowest altitude was \textit{12}12start text, 12, end text meters below the ground.
A positive (or negative) interval is a domain interval over which the function values are all positive (or negative).
Since A(t)>0A(t)>0A, left parenthesis, t, right parenthesis, is greater than, 0 over the interval [6.5,10][6.5,10]open bracket, 6, point, 5, comma, 10, close bracket, this is a positive interval. This means that between the \textit{6.5}6.5start text, 6, point, 5, end text- and \textit{10}10start text, 10, end text-minute marks, Keith was above the ground.
An increasing (or decreasing) interval is a domain interval over which the function values increase (or decrease) as the input variable increases.
In this graph, the interval, 5, point, 5, comma, 8, close bracket is an increasing interval. This means that between the end text-minute marks, the elevator was going up.