Answer:
Options C and E
Step-by-step explanation:
Option A. Circle
We can't get a cross section in the form of a circle.
Option B. Cube
We can't get a cross section in the form of a cube.
Option C. Rectangle
When we slice a rectangular pyramid parallel to the base but not through the vertex, we get a Rectangle.
Option D. Square
We can not get a square by slicing a rectangular pyramid.
Option E. Triangle
By slicing a rectangular pyramid perpendicular to the base and passing through the vertex we can get the cross section in the form of triangle.
Options C and E will be the answer.
Length= 9 width= 1
or
length= 8 width= 2
or
length= 7 width= 3
or
length= 6 width= 4
First, distribute what's inside the parenthesis, and change all the subtractions to addition of negatives.
18 + -2 (x^2 + - 5x)
Next distribute the -2
18 + -2x^2 + 10x
Then I like to rearrange stuff to put it in standard form.
-2x^2 + 10x + 18
The description expresses three points which can be used for a standard form equation. The vertex is stated to be (0,0) and is a maximum; two other points are (-21,-74) and (21,-74)
The equation for vertex form of a parabola:
y=a(x-h)^2+k
vertex (h,k)
thus our equation will be:
y=a(x-0)^2+0
thus
y=ax^2
using one of the points, the value of a will be:
-74=a(21)^2
a=-74/441
thus the equation will be:
y=-74/441x²
