Answer. First option: t > 6.25
Solution:
Height (in feet): h=-16t^2+729
For which interval of time is h less than 104 feet above the ground?
h < 104
Replacing h for -16t^2+729
-16t^2+729 < 104
Solving for h: Subtracting 729 both sides of the inequality:
-16t^2+729-729 < 104-729
-16t^2 < -625
Multiplying the inequality by -1:
(-1)(-16t^2 < -625)
16t^2 > 625
Dividing both sides of the inequality by 16:
16t^2/16 > 625/16
t^2 > 39.0625
Replacing t^2 by [ Absolute value (t) ]^2:
[ Absolute value (t) ]^2 > 39.0625
Square root both sides of the inequality:
sqrt { [ Absolute value (t) ]^2 } > sqrt (39.0625)
Absolute value (t) > 6.25
t < -6.25 or t > 6.25, but t can not be negative, then the solution is:
t > 6.25
Answer:
3,520 yds in 2 hours
Step-by-step explanation:
5,280:1 ; 1 mile an hour is 5,280 feet in an hour
10,560:2 ; 2 miles in 2 hours is 5,280+5,280 (10,560) feet in 2 hours
3 ft = 1 yd ; every 3 feet is a yard, so divide 10,560 by 3
10,560/3 = 3520 yds ; Jorge can walk 3,520 yds in 2 hours
Answer:
Maximum area = 800 square feet.
Step-by-step explanation:
In the figure attached,
Rectangle is showing width = x ft and the side towards garage is not to be fenced.
Length of the fence has been given as 80 ft.
Therefore, length of the fence = Sum of all three sides of the rectangle to be fenced
80 = x + x + y
80 = 2x + y
y = (80 - 2x)
Now area of the rectangle A = xy
Or function that represents the area of the rectangle is,
A(x) = x(80 - 2x)
A(x) = 80x - 2x²
To find the maximum area we will take the derivative of the function with respect to x and equate it to zero.
= 80 - 4x
A'(x) = 80 - 4x = 0
4x = 80
x = 
x = 20
Therefore, for x = 20 ft area of the rectangular patio will be maximum.
A(20) = 80×(20) - 2×(20)²
= 1600 - 800
= 800 square feet
Maximum area of the patio is 800 square feet.
Answer:
Yes
Step-by-step explanation:
