Talk:Trigonometry/Derivative of Cosine

More Detail Needed
Needs a justification for:
 * $$\lim_{h \rightarrow 0} \frac{\sin(\frac{h}{2})}{\frac{h}{2}} = 1$$

JamesCrook (discuss • contribs) 16:35, 11 March 2011 (UTC)


 * Sorry, I assumed that readers of Book 3 were supposed to be a little more sophisticated than readers of Book 1.--Wisden (discuss • contribs) 17:46, 15 March 2011 (UTC)