Answer :
To solve the problem of finding the time interval when Jerald is less than 104 feet above the ground, we'll use the given height formula:
[tex]\[ h = -16t^2 + 729 \][/tex]
We want his height, [tex]\( h \)[/tex], to be less than 104 feet:
[tex]\[ -16t^2 + 729 < 104 \][/tex]
Now, let's solve the inequality step-by-step:
1. Rearrange the inequality:
Subtract 104 from both sides:
[tex]\[ -16t^2 + 729 < 104 \][/tex]
[tex]\[ -16t^2 < 104 - 729 \][/tex]
[tex]\[ -16t^2 < -625 \][/tex]
2. Divide by -16:
Remember, when dividing by a negative number, the inequality sign flips:
[tex]\[ t^2 > \frac{625}{16} \][/tex]
3. Calculate the critical points:
Find the square root of both sides:
[tex]\[ t > \frac{25}{4} \][/tex]
[tex]\[ t > 6.25 \text{ or } t < -6.25 \][/tex]
Since time [tex]\( t \)[/tex] cannot be negative in this context (because Jerald cannot jump back in time), we only consider [tex]\( t > 6.25 \)[/tex].
4. Conclusion:
Jerald’s height will be less than 104 feet when [tex]\( t > 6.25 \)[/tex].
Therefore, the correct interval of time during which Jerald is less than 104 feet above the ground is:
[tex]\[ t > 6.25 \][/tex]
[tex]\[ h = -16t^2 + 729 \][/tex]
We want his height, [tex]\( h \)[/tex], to be less than 104 feet:
[tex]\[ -16t^2 + 729 < 104 \][/tex]
Now, let's solve the inequality step-by-step:
1. Rearrange the inequality:
Subtract 104 from both sides:
[tex]\[ -16t^2 + 729 < 104 \][/tex]
[tex]\[ -16t^2 < 104 - 729 \][/tex]
[tex]\[ -16t^2 < -625 \][/tex]
2. Divide by -16:
Remember, when dividing by a negative number, the inequality sign flips:
[tex]\[ t^2 > \frac{625}{16} \][/tex]
3. Calculate the critical points:
Find the square root of both sides:
[tex]\[ t > \frac{25}{4} \][/tex]
[tex]\[ t > 6.25 \text{ or } t < -6.25 \][/tex]
Since time [tex]\( t \)[/tex] cannot be negative in this context (because Jerald cannot jump back in time), we only consider [tex]\( t > 6.25 \)[/tex].
4. Conclusion:
Jerald’s height will be less than 104 feet when [tex]\( t > 6.25 \)[/tex].
Therefore, the correct interval of time during which Jerald is less than 104 feet above the ground is:
[tex]\[ t > 6.25 \][/tex]