Re: Integrate is driving me crazy, please help!

*To*: mathgroup at smc.vnet.net*Subject*: [mg56215] Re: Integrate is driving me crazy, please help!*From*: Helen Read <hpr at together.net>*Date*: Tue, 19 Apr 2005 04:55:33 -0400 (EDT)*References*: <d3vn1h$jm9$1@smc.vnet.net>*Reply-to*: read at math.uvm.edu*Sender*: owner-wri-mathgroup at wolfram.com

Jim Martin wrote: > Hello Mathematica Experts: > > I am a biomechanist and work mostly in the area of muscle contraction. I > do a lot of numerical computations using excel, but right now I need an > analytical solution that represents force as a function of position > integrated over a shortening amplitude. I downloaded a trial version of > Mathematica and have tried to obtain a solution for this: > > Integrate[(hillb*((f0 + hilla)/(2*pi*f*a*Cos(ArcSin(x/a)) + hillb))) - > hilla, {x, -a, a}] The number pi is denoted Pi in Mathematica. Remember that *all* built-in functions, constants, etc., begin with a capital letter. And argument(s) of a function are always enclosed within square brackets. f[x], Sin[x], Log[x], etc. So what you need is the following. Integrate[(hillb*((f0 + hilla)/(2*Pi*f*a*Cos[ArcSin[x/a]] + hillb))) - hilla, {x, -a, a}] -- Helen Read University of Vermont