Answer :
To solve the problem, we need to determine when Jerald's height is less than 104 feet above the ground. The equation modeling his height is given by:
[tex]\[ h = -16t^2 + 729 \][/tex]
We want to find the interval of time [tex]\( t \)[/tex] when his height [tex]\( h \)[/tex] is less than 104 feet, so we set up the inequality:
[tex]\[ -16t^2 + 729 < 104 \][/tex]
Let's solve this step-by-step:
1. Subtract 104 from both sides:
[tex]\[ -16t^2 + 729 - 104 < 0 \][/tex]
[tex]\[ -16t^2 + 625 < 0 \][/tex]
2. Rearrange the inequality:
[tex]\[ -16t^2 < -625 \][/tex]
3. Divide both sides by -16. Remember, dividing by a negative reverses the inequality sign:
[tex]\[ t^2 > \frac{625}{16} \][/tex]
4. Simplify the fraction:
[tex]\[ t^2 > 39.0625 \][/tex]
5. Take the square root of both sides:
[tex]\[ t > \sqrt{39.0625} \][/tex]
[tex]\[ t > 6.25 \][/tex]
Since Jerald's height must also be less than 104 feet above the ground and time cannot be negative, the valid interval is when [tex]\( t \)[/tex] is greater than 6.25. Therefore, the interval for which Jerald is less than 104 feet above the ground is:
[tex]\[ t > 6.25 \][/tex]
Thus, among the given options, [tex]\( t > 6.25 \)[/tex] is the correct choice.
[tex]\[ h = -16t^2 + 729 \][/tex]
We want to find the interval of time [tex]\( t \)[/tex] when his height [tex]\( h \)[/tex] is less than 104 feet, so we set up the inequality:
[tex]\[ -16t^2 + 729 < 104 \][/tex]
Let's solve this step-by-step:
1. Subtract 104 from both sides:
[tex]\[ -16t^2 + 729 - 104 < 0 \][/tex]
[tex]\[ -16t^2 + 625 < 0 \][/tex]
2. Rearrange the inequality:
[tex]\[ -16t^2 < -625 \][/tex]
3. Divide both sides by -16. Remember, dividing by a negative reverses the inequality sign:
[tex]\[ t^2 > \frac{625}{16} \][/tex]
4. Simplify the fraction:
[tex]\[ t^2 > 39.0625 \][/tex]
5. Take the square root of both sides:
[tex]\[ t > \sqrt{39.0625} \][/tex]
[tex]\[ t > 6.25 \][/tex]
Since Jerald's height must also be less than 104 feet above the ground and time cannot be negative, the valid interval is when [tex]\( t \)[/tex] is greater than 6.25. Therefore, the interval for which Jerald is less than 104 feet above the ground is:
[tex]\[ t > 6.25 \][/tex]
Thus, among the given options, [tex]\( t > 6.25 \)[/tex] is the correct choice.