<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:
see explanation
Step-by-step explanation:
∠1 = 58° ( alternate angles )
∠1 and ∠2 form a straight angle and are supplementary, thus
∠2 = 180° - 58° = 122°
Use distributive method
5r - 50 = -51
Add 50
5r = -1
Divide by 5
r = -1/5
The definition of a complementary angle is one angle who can be added to another complementary angle to sum to 90 degrees. More simply, just an angle is complementary to another angle if they add up to 90 degrees. In this case, to find the other angle, you subtract 24 from 90 which equals 66 degrees.
