Re: How to solve a simple Trig cofunction?

*To*: mathgroup at smc.vnet.net*Subject*: [mg50517] Re: [mg50500] How to solve a simple Trig cofunction?*From*: DrBob <drbob at bigfoot.com>*Date*: Thu, 9 Sep 2004 05:17:28 -0400 (EDT)*References*: <200409080914.FAA08518@smc.vnet.net>*Reply-to*: drbob at bigfoot.com*Sender*: owner-wri-mathgroup at wolfram.com

eqn = Cos[x + 4] == Sin[3x + 2]; Reduce[eqn && 0 ? x ? Pi/2, x]; x /. ToRules[%] %/Degree//N (1/2)*(-3 + 2*Pi - 2*ArcTan[1 + Sqrt[2]]) 26.556330730376516 The symbolic answer is in radians (if evaluated) but the numeric one is in degrees. Bobby On Wed, 8 Sep 2004 05:14:59 -0400 (EDT), Brian Feeny <bfeeny at mac.com> wrote: > Lets say I have: > > cos[X+4] = sin[3X+2] > > What would be the proper way to solve the above, for X, in > Mathematica, with the answer in degrees? > > I did this, but something tells me their has to be a better way: > > NSolve[Cos[X Degree +4 Degree] = Sin[3 X Degree+2 Degree], X] > > I mean, I wish i didn't have to enter "Degree"so many times, perhaps > their is a simple way to just tell it the whole thing is in Degree. > > Additionally, is their a way to constrain the above to 90 > X > 0? I > tried doing like: > > NSolve[Cos[X Degree +4 Degree] = Sin[3 X Degree+2 Degree], X /; 90 >> X>0] > > but that obviously is not the right way since that doesn't work. > Appreciate all the help. > > Brian > > > -- DrBob at bigfoot.com www.eclecticdreams.net

**References**:**How to solve a simple Trig cofunction?***From:*bfeeny@mac.com (Brian Feeny)