9. The height of a ball at a given time can be modelled with the quadratic function
\( h ( t ) = - 5 t ^ { 2 } + 20 t + 1 \) , where height, \( h ( t ) \) , is in metres and time, \( t \) , is in seconds. How long is the ball in the air?
Pregunta
Answer
\(t = 2 + \sqrt { \frac { 21 } { 5 } }\)
Related Questions
Q:
Find the inverse for each of the following functions.
\(f ( x ) = 3 x + 1\)
\(g ( x ) = 1 x ^ { 3 } - 5\)
\(h ( x ) = \frac { 3 } { x + 5 }\)
\(j ( x ) = \sqrt[ 3 ] { x + 1 }\)
Q:
The total revenue from the sale of a popular book is approximated by the rational function \( R ( x ) = \frac { 1700 x ^ { 2 } } { x ^ { 2 } + 4 } \) , where \( x \) is the number of years since publication and \( R ( x ) \)
is the total revenue in millions of dollars.
(a) Find the total revenue at the end of the first year.
(b) Find the total revenue at the end of the second year.