Answer:
Option A.
Step-by-step explanation:
Based on the information provided on the question
the function used to model Tony's run is:
f(x) = -250*x + 5000
This means that after x = 20 minutes, Tony will arrive to the finish line
f(20) = -250*(20) + 5000 = -5000 + 5000 = 0
The function is always decreasing, because we are dealing with a line with negative slope.
Option A.
we are given
differential equation as
![y'''-9y''+20y'=0](https://tex.z-dn.net/?f=y%27%27%27-9y%27%27%2B20y%27%3D0)
we are given
![y=e^{rx}](https://tex.z-dn.net/?f=y%3De%5E%7Brx%7D)
Firstly, we will find y' , y'' and y'''
those are first , second and third derivative
First derivative is
![y'=re^{rx}](https://tex.z-dn.net/?f=y%27%3Dre%5E%7Brx%7D)
Second derivative is
![y''=r*re^{rx}](https://tex.z-dn.net/?f=y%27%27%3Dr%2Are%5E%7Brx%7D)
![y''=r^2e^{rx}](https://tex.z-dn.net/?f=y%27%27%3Dr%5E2e%5E%7Brx%7D)
Third derivative is
![y'''=r^2*re^{rx}](https://tex.z-dn.net/?f=y%27%27%27%3Dr%5E2%2Are%5E%7Brx%7D)
![y'''=r^3e^{rx}](https://tex.z-dn.net/?f=y%27%27%27%3Dr%5E3e%5E%7Brx%7D)
now, we can plug these values into differential equation
and we get
![r^3 e^{rx}-9r^2 e^{rx}+20re^{rx}=0](https://tex.z-dn.net/?f=r%5E3%20e%5E%7Brx%7D-9r%5E2%20e%5E%7Brx%7D%2B20re%5E%7Brx%7D%3D0)
now, we can factor out common terms
![e^{rx}(r^3 -9r^2 +20r)=0](https://tex.z-dn.net/?f=e%5E%7Brx%7D%28r%5E3%20-9r%5E2%20%2B20r%29%3D0)
we can move that term on right side
![(r^3 -9r^2 +20r)=0](https://tex.z-dn.net/?f=%28r%5E3%20-9r%5E2%20%2B20r%29%3D0)
now, we can factor out
![r(r^2 -9r +20)=0](https://tex.z-dn.net/?f=r%28r%5E2%20-9r%20%2B20%29%3D0)
![r(r-5)(r-4)=0](https://tex.z-dn.net/?f=r%28r-5%29%28r-4%29%3D0)
now, we can set them equal
![r=0](https://tex.z-dn.net/?f=r%3D0)
![r-5=0](https://tex.z-dn.net/?f=r-5%3D0)
![r=5](https://tex.z-dn.net/?f=r%3D5)
![r-4=0](https://tex.z-dn.net/?f=r-4%3D0)
![r=4](https://tex.z-dn.net/?f=r%3D4)
so, we will get
...............Answer
Answer:
5 blocks
Step-by-step explanation:
5 blocks for every barometer
First term is -7, so a_1 = -7
To get the next term, we add on 4. We can see this if we subtract like so
d = (2nd term) - (1st term) = (-3) - (-7) = -3+7 = 4
So d = 4 is the common difference.
Apply a_1 = -7 and d = 4 to get...
a_n = a_1 + d*(n-1)
a_n = -7 + 4*(n-1)
a_n = -7 + (n-1)*4
Answer: Choice A
The area bounded by the 2 parabolas is A(θ) = 1/2∫(r₂²- r₁²).dθ between limits θ = a,b...
<span>the limits are solution to 3cosθ = 1+cosθ the points of intersection of curves. </span>
<span>2cosθ = 1 => θ = ±π/3 </span>
<span>A(θ) = 1/2∫(r₂²- r₁²).dθ = 1/2∫(3cosθ)² - (1+cosθ)².dθ </span>
<span>= 1/2∫(3cosθ)².dθ - 1/2∫(1+cosθ)².dθ </span>
<span>= 9/8[2θ + sin(2θ)] - 1/8[6θ + 8sinθ +sin(2θ)] .. </span>
<span>.............where I have used ∫(cosθ)².dθ=1/4[2θ + sin(2θ)] </span>
<span>= 3θ/2 +sin(2θ) - sin(θ) </span>
<span>Area = A(π/3) - A(-π/3) </span>
<span>= 3π/6 + sin(2π/3) -sin(π/3) - (-3π/6) - sin(-2π/3) + sin(-π/3) </span>
<span>= π.</span>