The staircase has treads that are 10 inches deep with 7 inch high risers. If the staircase needs to reach a total height of 8 feet, 2 inches. How much floor space needs to be allowed for the staircase?

140 inches

Step-by-step explanation:

The design of the staircase treads is 10 inches deep and 7 inches rise.

The total height of the staircase is 8 feet and 2 inches.

Present the height of staircase in inches as;

1 foot = 12 inches

8 ft=?

Apply cross-product as (8*12)/1 =96 inches

Total height in inches of the staircase= 96+2 = 98 inches

Finding the number of times the tread's height fits in the total height will be;

98/7 =14 times

The floor space for the staircase will thus be; 10*14 =140 inches

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this