Homework Statement
this problem was on my finals and i stared at it for 30 mins straight and still didn't figure it out and now it just bothers me that i don't know how to do the first problem on my final exam.
"find the general solution to the dfq"
xy'+xy= 1-y
Homework Equations...
thanks for responding, Lets see if i have the yp's correct
yp = (At^2+Bt+c)e^-t
y'p = (2At + B)e^-t -(At^2+Bt+c)e^-t
y''p = 2Ae^-t - (2At + B)e^-t - (2At+B)e^-t -(At^2+Bt+c)e^-t
Homework Statement
Find the general solution to the diff equation using undetermined coefficients
y''-2y'-3y = 3te^-1
Homework Equations
The Attempt at a Solution
r^2 - 2r -3 = 0
r = -1, 3
so y = c1 e^-t + c2e^3t + yp
since e^-t already exists as a solution, i have to...
Homework Statement
Find y2 given
t^2y'' + 3ty' + y = 0 y1(t) = 1/t
Homework Equations
The Attempt at a Solution
i found y, y' and y'' and plugged it back in to the Differential equation,
after doing some work, i'm basicly down to
tv''+v' = 0
where y2 = v/t
so u =...
Homework Statement
Solving this differential equation
ty' + 2y = t^2 - t + 1
Homework Equations
Its linear so i set it up in linear form
y' + y(2/t) = t - 1 +1/t
The Attempt at a Solution
the integrating factor (u) = e ^ integral (ydt) = e^ integral (2dt/t)...
Here's the...
Homework Statement
There is a large bed floating in sea with the density of 765 kg/m^3. What fraction of the bed's volume will be under the surface of the water? The density of sea water is 1035 kg/m^3.
Homework Equations
Fb = Density * v * gravity
The Attempt at a Solution
I know...
Homework Statement
A small cube (m=0.450 kg) is at a height of 393 cm up a frictionless track which has a loop of radius, R = 58.95 cm at the bottom. The cube starts from rest and slides freely down the ramp and around the loop. Find the speed of the block when it is at the top of the loop...
Isn't that what i did? B = Density * V * g and like you said water is fairly constant, so V = B/g
which is 34N/9.8 = 3.47 which is the volume of the object, right?
So now i can do D = m/v for the density of the object given m of object is 341/9.8.
And i just confused myself, we're ignoring the...