Homework Statement
Show that the descriminant of the characteristic polynomial of K is greater than 0.
K=\begin{pmatrix}-k_{01}-k_{21} & k_{12}\\
k_{21} & -k_{12}
\end{pmatrix}
And k_i > 0
Homework Equations
b^2-4ac>0
The Attempt at a Solution
I have tried the following...
Homework Statement
y''+0.1y'+y=1+2\sum_{k=1}^{n}(-1)^{k}u_{k\pi}(t)
and quiescent initial conditions.
Homework Equations
None.
The Attempt at a Solution
(s^{2}+0.1s+1)Y(s)=\mathcal{L}\{1\}+2\sum_{k=1}^{n}(-1)^{k}\mathcal{L}\big\{ u_{k\pi}(t)\big\}
I'm not sure if this step was...
Homework Statement
A 50 N sign is suspended by two cables that make angles of 25 degrees and 70 degrees with the horizontal. Determine the tension in each cable.
Homework Equations
Cosine law, sine law, or trig
The Attempt at a Solution
I believe that the teacher's answer is wrong. She...