we are given
To find x-intercept means we have to find zeros
and for finding zeros , we will use quadratic formula
and we have it has two x-intercepts
so, it's discriminant must be greater than 0
so, we will find discriminant
now, we can compare with
and then we can find a , b and c
now, we can find D
It has two x-intercepts
so,
now, we can solve for m
............Answer
Answer
Josh's textbook reached the ground first
Josh's textbook reached the ground first by a difference of
Step-by-step explanation:
Before we proceed let us re write correctly the height equation which in correct form reads:
Eqn(1).
Where:
: is the height range as a function of time
: is the initial velocity
: is the initial heightin feet and is given as 40 feet, thus Eqn(1). becomes:
Eqn(2).
Now let us use the given information and set up our equations for Ben and Josh.
<u>Ben:</u>
We know that
Thus Eqn. (2) becomes:
Eqn.(3)
<u>Josh:</u>
We know that
Thus Eqn. (2) becomes:
Eqn. (4).
<em><u>Now since we want to find whose textbook reaches the ground first and by how many seconds we need to solve each equation (i.e. Eqns. (3) and (4)) at </u></em><em><u>. Now since both are quadratic equations we will solve one showing the full method which can be repeated for the other one. </u></em>
Thus we have for Ben, Eqn. (3) gives:
Using the quadratic expression to find the roots of the quadratic we have:
Since time can only be positive we reject the solution and we keep that Ben's book took
seconds to reach the ground.
Similarly solving for Josh we obtain
Thus again we reject the negative and keep the positive solution, so Josh's book took seconds to reach the ground.
Then we can find the difference between Ben and Josh times as
So to answer the original question:
<em>Whose textbook reaches the ground first and by how many seconds?</em>