Answer:
The solutions are
t=2.07 sec and t=5.43 sec
Step-by-step explanation:
The question in English
The height h above ground level (in feet) of a toy rocket, t seconds after it is launched, is given by h = -16t2 + 120t. When will the rocket be 180 feet above the ground?
we have
[tex]h=-16t^{2}+120t[/tex] -----> equation A
[tex]h=180[/tex] -----> equation B
equate the equation A and equation B
[tex]180=-16t^{2}+120t[/tex] ------> equation C
we know that
The solution of the equation C is equal to the x-coordinate of the intersection point of the graph equation A and the graph of the equation B
so
using a graphing tool
The solutions are
t=2.07 sec and t=5.43 sec
see the attached figure to better understand the problem
