Use symmetry to evaluate the double integral of $f(x,y)=xy$ over the region $R$, where $R$ is the disk $x^2+y^2\le 4$.

Let $f(x,y)=x^2+3y^2$. Find the maximum rate of change of $f$ at the point $(1,2)$ and the direction in which it occurs.

Find the exact length of the curve $y=2\surd 3x^{\frac{3}{2}}$ for $0\le x\le 6$.

Find the global maximum and minimum values of the function $f(x,y)=e^{-xy}$ on the region defined by $x^2+4y^2\le 1$.

Find the length of the loop of the curve given by $x=6t-2t^3$, $y=6t^2$.

Find the exact length of the curve $y=\ln (\sec (x\left)\right)$ for $0\le x\le \frac{\pi }{6}$.

Which of the following points is a location where the function $f\left(x\right)=\frac{1}{x-2}$ is discontinuous?

Find the critical points of the given function.

$g(x)=\frac13x^3-\frac12x^2-12x$

Find the critical points of the given function.

$f(t)=\frac{6t}{t^2+1}$