rolling-eqn.html: Add trailing punctuation to equations.

As noted elsewhere, I've decided that Ian Stewart was wrong about
this.

diff --git a/rolling-eqn.html b/rolling-eqn.html
index 9588d54fb39b96d5da44a7d12d0475f78473fbc7..4b5a9739db90545a37a7b783926fb677ac970482 100644 (file)
--- a/rolling-eqn.html
+++ b/rolling-eqn.html
@@ -26,22 +26,22 @@ here’s how it currently works.
 <p>Let&rsquo;s suppose we start with square wire, with side&nbsp;$S$,
 and we roll it to thickness&nbsp;$t$.  Then we find that the
 wire&rsquo;s width is
-\[ w = \sqrt{\frac{S^3}{t}} \]
+\[ w = \sqrt{\frac{S^3}{t}} \,\text{.} \]
 Rearranging, we find that
-\[ S = \sqrt[3]{w^2 t} \]
+\[ S = \sqrt[3]{w^2 t} \,\text{.} \]
 For round wire, we assume that the cross-section area is the important
 bit, so a round wire with diameter&nbsp;$D$ ought to work as well as
 square wire with side $S$ if $S^2 = \pi D^2/4$, i.e.,
-\[ D = \sqrt{\frac{4 S^2}{\pi}} = \frac{2 S}{\sqrt\pi} \]
+\[ D = \sqrt{\frac{4 S^2}{\pi}} = \frac{2 S}{\sqrt\pi} \,\text{.} \]
 Volume is conserved, so if the original and final wire lengths
 are&nbsp;$L$ and&nbsp;$l$ respectively, then
-\[ L S^2 = l w t \]
+\[ L S^2 = l w t \,\text{,} \]
 and hence
-\[ L = \frac{l w t}{S^2} \]
+\[ L = \frac{l w t}{S^2} \,\text{.} \]
 Finally, determining the required initial stock length&nbsp;$L_0$ given
 its side&nbsp;$S_0$ (for square stock) or diameter&nbsp;$D_0$ (for
 round) again makes use of conservation of volume:
-\[ L_0 = \frac{S^2 L}{S_0^2} = \frac{4 S^2 L}{\pi D_0^2} \]
+\[ L_0 = \frac{S^2 L}{S_0^2} = \frac{4 S^2 L}{\pi D_0^2} \,\text{.} \]
 
 <p>[This page uses <a href="https://www.mathjax.org/">MathJax</a> for
 rendering equations.  It probably doesn&rsquo;t work if you don&rsquo;t