\vec{u}\circ\vec{v}=|\vec{u}|\cdot|\vec{v}|\cos\angle(\vec{u},\vec{v})=-1\Rightarrow
\cos\angle(\vec{u},\vec{v})<0\Rightarrow 90^o<\angle(\vec{u},\vec{v})<270^o
the same direction: \cos\angle(\vec{u},\vec{v})=\cos 0^o=1\Rightarrow \vec{u}\circ\vec{v}\ge 0>-1 so not B...
Improper integral ##\int_{-\infty}^\infty f(x)\,dx## is converged if both integrals ##\int_{-\infty}^af(x)\,dx## and ##\int_a^\infty f(x)\,dx## are convergent. Cauchy principal value is a limit ##\lim\limits_{a\to\infty}\int_{-a}^af(x)\,dx## and it may exist even if ##\int_{-\infty}^\infty...
Yes, you have ##\int_0^tf(\tau,t)\,d\tau## in the integral instead of ##\int_0^tf(\tau)\,d\tau## and the formula for integral doesn't work. This is convolution so:
##L\{1*t^3\}=L\{1\}\cdot L\{t^3\}##
Mhorton91, how did you get:
##-\frac{y}{yz}=x-x##
from:
##-y=xyz-x##
You can't divide one term on the right side by ##yz## and leave the other unchanged.