(Spotted by Dr. Elliott Bertrand)
In the statement of the problem on page 18,
the equation $x^2+y^2=c$ is meant to be be $x^2+y^2=c^2$.
That incorrect form of the equation appears two more times
in the second paragraph on page 19. Additionally,
at the end of that paragraph the expressions
$y = + \sqrt{c-x^2}$ and
$y = - \sqrt{c-x^2}$
should be
$y = + \sqrt{c^2-x^2}$ and
$y = - \sqrt{c^2-x^2}$.
Furthermore, the statement of the problem on page 18 is
garbled. The line
$\quad$“where $c$ is a positive constant and is an implicit
solution of $\ldots$”
should be
$\quad$“where $c$ is a positive constant, is an implicit
solution of$\ldots$ ”.
