Look-alike functions. - Printable Version +- Tetration Forum (https://math.eretrandre.org/tetrationforum) +-- Forum: Tetration and Related Topics (https://math.eretrandre.org/tetrationforum/forumdisplay.php?fid=1) +--- Forum: Mathematical and General Discussion (https://math.eretrandre.org/tetrationforum/forumdisplay.php?fid=3) +--- Thread: Look-alike functions. (/showthread.php?tid=1070) Look-alike functions. - tommy1729 - 03/07/2016 Consider the argument of An entire function within a unit radius. If they are identical for 2 distinct entire function with that radius we call them " look-alike ". For instance 2sinh(z+3) and exp(z+3) are look-alikes. You might have noticed that all look-alikes to the above satisfy F ' ' (z) = F(z). So yes this relates to differential equations. I think cauchy-riemann matters. This is probably isomorphic to something well understood. Regards Tommy1729 RE: Look-alike functions. - hixidom - 03/08/2016 sinh(t) is defined in terms of exp(t). Why is it notable that they are similar sometimes?