Answer:
the total amount of water supplier per hour to the region within a circle of radius R=110 ( that is from distance r, 0<r<110)
![W(R) = 2\pi [1-(R+1)e^{-R}]](https://tex.z-dn.net/?f=W%28R%29%20%3D%202%5Cpi%20%5B1-%28R%2B1%29e%5E%7B-R%7D%5D)
Step-by-step explanation:
if f(r) describes the water supplied at a distance r , the total amount supplied inside a region that goes from 0 until the circle of radius R, is the sum of all f(r) values from 0 until R, that is the integral value over these limits.
The formula deduction can be found in the attached picture
There is an "r" that multiplies e^-r as result of changing from rectangular coordinates to polar ones.(dx*dy --> r*dr*da)
Answer: the number of students that were surveyed is 40
Step-by-step explanation:
Let x = total number of students that were surveyed about their favorite colors
1/4 of the students preferred red.
This means that the number of students that preferred red is 1/4 × x = x/4
1/8 of the students preferred blue.
This means that the number of students that preferred blue is 1/8 × x = x/8
The remaining number of students will be the total number of students - the sum of the number of students that preferred red and the number of students that preferred blue. It becomes
x - (x/4 + x/8) = x - 3x/8 = 5x/8
3/5 of the remaining students were for green. This means that the number of students that preferred green is 3/5 × 5x/8 = 3x/8
if 15 students prefer green, then
3x/8 = 15
3x = 120
x = 120/3 = 40 students
First, distribute the minus sign across the second set. So you have:
x - y + 1 - x - y + 1
Now, we combine like terms:
x-x=0
-y-y=-2y
1+1=2
So we have -2y+2
Hope that helps.
Answer:
(7, 0) and (-5, 0)
Step-by-step explanation:
<u>Vertex form</u>
(where (h, k) is the vertex)
Given:

Given:



Therefore:

The x-intercepts are when y = 0






Therefore, the x-intercepts are (7, 0) and (-5, 0)
Answer:
2.75
Step-by-step explanation:
let x be the number.
0.75 + 2 = x
2.75 = x