Introductio in analysin infinitorum

FACTORUM TRINOMIALIUM. 125 nique forma secunda per quartam eritque $\frac{e^y+e^{-y}-e^c-e^{-c}}{2-e^c-e^{-c}}$ $=(1-\frac{yy}{cc})(1-\frac{2cy+yy}{4\pi\pi+cc})(1+\frac{2cy+yy}{4\pi\pi+cc})(1-\frac{2cy+yy}{16\pi\pi+cc})(1+\frac{2cy+yy}{16\pi\pi+cc})(1-\frac{2cy+yy}{36\pi\pi+cc}) \&\text{c.}$ 163. Hæ quatuor combinationes nunc commode ad Circulum transferri possunt, ponendo $c=g\sqrt{-1}$ & $y=v\sqrt{-1}$: erit enim $e^{v\sqrt{-1}}+e^{-v\sqrt{-1}} = 2\text{cof.}v$; $e^{v\sqrt{-1}}-e^{-v\sqrt{-1}} = 2\sqrt{-1}.\text{sin.}v$. & $e^{g\sqrt{-1}}+e^{-g\sqrt{-1}} = 2\text{cof.}g$; $e^{g\sqrt{-1}}-e^{-g\sqrt{-1}} = 2\sqrt{-1}.\text{sin.}g$. Hinc prima [TRUNCATED]