Toronto Math Forum
MAT2442013S => MAT244 MathTests => Final Exam => Topic started by: Victor Ivrii on April 17, 2013, 03:02:14 PM

\begin{equation*}
y^{(4)} 3y''4y = \sin (t)+8 t.
\end{equation*}

solve homogeneous> roots are i,i,2,2
Yh=c1 e^2t +c2 e^2t +c3 cost +c4 sint
Yp> undetermined coefficients> Yp= Atcost +Btsint +Ct +D
evaulate polynomial terms => C=2. D=0
evaulate sinusoidal terms => A=1/10 B=0
Y= c1 e^2t +c2 e^2t +c3 cost +c4 sint + (1/10)tcost 2t

Also, I MIGHT have used 'x' instead of 't' on the test, would I lose marks if I used the wrong variable?

i did this

Solutions

Benny, WTH you posted Q1 into FE3 and Q3 into FE1 (so I needed to split and merge)?