SOLUTION: A monkey throws a nut down to the ground from a branch 15 m up. The function ℎ(t) = −5t^2 − 10t + 15 models the height of the nut, in metres, and t is the time in seconds.

Algebra ->  Finance -> SOLUTION: A monkey throws a nut down to the ground from a branch 15 m up. The function ℎ(t) = −5t^2 − 10t + 15 models the height of the nut, in metres, and t is the time in seconds.       Log On


   

Question 1162225: A monkey throws a nut down to the ground from a branch 15 m up. The function
ℎ(t) = −5t^2 − 10t + 15 models the height of the nut, in metres, and t is the time in seconds.
a) Which zero needs to be discarded? Why?
Answer by ikleyn(52864) About Me  (Show Source):
You can put this solution on YOUR website!
.

Solve the quadratic equation  


    h(t) = 0,   which is  -5t^2 - 10t + 15 = 0.


Accept only positive root t > 0 and discard the negative root, since this equation, by its construction,

is valid (makes physical sense) for positive values of the parameter t, only.