Find the exact length of the polar curve $r=2$, for $0\le \theta \le 4\pi$.

Which of the following best describes the contour lines (level curves) of the function $f(x,y)=x^2+7y^2$?

Let $r\left(t\right)$ be the vector-valued function defined by $r\left(t\right)=(3t,\frac{1}{t+1},e^{-t})$. Evaluate the definite integral from $t=0$ to $t=1$ of $r\left(t\right)dt$.

Find the exact length of the curve $y=\frac{1}{4}{x}^2-\frac{1}{2}\ln \left(x\right)$ for $1\le x\le 4$.

Evaluate the line integral of the vector field $F(x,y)=(2x,3y)$ along the curve $C$ given by the vector function $r\left(t\right)=(t,t^2)$, where $t$ goes from $0$ to $1$.

How does the graph of the catenary y = a cosh x/a change as a > 0 increases?

101–104. Proving identities Prove the following identities.

cosh (x + y) = cosh x cosh y + sinh x sinh y

61–62. Points of intersection and area

a. Sketch the graphs of the functions f and g and find the x-coordinate of the points at which they intersect.

f(x) = sech x, g(x) = tanh x; the region bounded by the graphs of f, g, and the y-axis

State the inputs and outputs of the following relation. Is it a function? $\{(-3,5),(0,2),(3,5)\}$