<span>First of all, there should be coherence for the units of measurement -- either they are all meters or they are all ft. I would assume they are all ft.
The correct answer is 75 ft above. T
The explanation is the following: suppose the ground level is the x-axis, the 2 feet of the arch lie respectively on (0,0) and (100,0) on the ground level. Since the arch is 100ft high, the vertex of the parabola will be the point (100,100). Thus, we can find the equation describing the parabola by putting the three points we know in a system and we find that the equation of the parabola is y=(-1/100)x^2+2
To find the focus F, we apply the formula for the focus of a vertical axis parabola, i.e. F(-b/2a;(1-b^2+4ac)/4a).
By substituting a=-1/100, b=2 and c=0 into the formula, we find that the coordinates of the focus F are (100,75).
So we conclude that the focus lies 75ft above ground.</span>
Answer:
a. b=4
Step-by-step explanation:
From the attached triangle drawn below:
NL=20, LM=3b, 
Since we are told that:
The correct option is A.
Answer:
(A) 2 meter
Step-by-step explanation:
It is given that the ladder forms a 72º angle with the ground and rests against the house at a spot that is 6 meters high.
Let the measure of bottom of the ladder from the wall be x, then using the trigonometry, we have
≈
Thus, option A is correct.
Answer:
120 pounds
Step-by-step explanation:
65% of y= 78 pounds
× y = 78 pounds
65y = 78 × 100=7800
y= 7800/65= 120 pounds
Answer:
$93.50
Step-by-step explanation:
81.30 x 1.15 = 93.50
