H=-16t^2+56t+1, the airplane is shot up from a platform 1 foot above the ground, so 1= - 16t^2+56t+1, we solve this equation
(- 16t+56)t=0, (- 16t+56)=0 or t=o, - 16t+56=0, implies t =3.5s
so the answer is C)3.5 seconds

4 0

3 years ago

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Let y′′′−9y′′+20y′=0. find all values of r such that y=erx satisfies the differential equation. if there is more than one correc

DerKrebs [107]

we are given

differential equation as

$y'''-9y''+20y'=0$

we are given

$y=e^{rx}$

Firstly, we will find y' , y'' and y'''

those are first , second and third derivative

First derivative is

$y'=re^{rx}$

Second derivative is

$y''=r*re^{rx}$

$y''=r^2e^{rx}$

Third derivative is

$y'''=r^2*re^{rx}$

$y'''=r^3e^{rx}$

now, we can plug these values into differential equation

and we get

$r^3 e^{rx}-9r^2 e^{rx}+20re^{rx}=0$

now, we can factor out common terms

$e^{rx}(r^3 -9r^2 +20r)=0$

we can move that term on right side

$(r^3 -9r^2 +20r)=0$

now, we can factor out

$r(r^2 -9r +20)=0$

$r(r-5)(r-4)=0$

now, we can set them equal

$r=0$

$r-5=0$

$r=5$

$r-4=0$

$r=4$

so, we will get

$r=0,4,5$ ...............Answer

4 0

3 years ago

. Data was collected on shoulder girth and height of a group of 25 individuals. The mean shoulder girth is 107.20 cm with a stan

snow_lady [41]

Answer:

ion even know

Step-by-step explanation:

6 0

3 years ago

Find the length of the third side. If necessary, round to the nearest tenth. 4 7

Natalija [7]

Can you show a picture of the question

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3 years ago

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