<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:
37
Step-by-step explanation:
Margin of error = critical value × standard error
For 98% confidence, CV = 2.326 (from t table).
Standard error is σ / √n, where σ is the population standard deviation, and n is the sample size.
Plugging in:
5 = 2.326 × 13 / √n
n = 36.6
Rounding up, n = 37.
Answer:
its 6x
Step-by-step explanation:
Answer:
The equations shows a difference of squares are:
<u>10y²- 4x²</u> $ <u>6y²- x²</u>
Step-by-step explanation:
the difference of two squares is a squared number subtracted from another squared number, it has the general from Ax² - By²
We will check the options to find which shows a difference of squares.
1) 10y²- 4x²
The expression is similar to the general form, so the equation represents a difference of squares.
It can be factored as (√10 y + 2x )( √10 y - 2x)
2) 6y²- x²
The expression is similar to the general form, so the equation represents a difference of squares.
It can be factored as (√6y + x )( √6y - x)
3) 8x²−40x+25
The expression is not similar to the general form, so the equation does not represent a difference of squares.
4) 64x²-48x+9
The expression is not similar to the general form, so the equation does not represent a difference of squares.
