## Calculus (3rd Edition)

The solutions: $c(t)=(4+t,1+2t)$ and $c(t)=(4+3t,1+6t)$
Using equation (3), the line through $(4,1)$ of slope 2 is parametrized by $x=4+r t$, ${}$ ${}$ $y=1+s t$, ${}$ ${}$ \$-\infty