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| Maybe this will help you a little sol=Simplify[{x[t],y[t]}/.DSolve[{x''[t]==b x'[t],y''[t]==-b y'[t]-g,x[0]==0,y[0]==0,x'[0]==v Cos[theta],y'[0]==v Sin[theta]},{x,y},t][[1]]]; yy[t_]:=sol[[2]];yy[t] xx[t_]:=sol[[1]];xx[t] which... |
| The usual method of limiting variables in solve in WolframAlpha is solve x^2=4,x>0 for x You can try that with and without the ,x>0 and see the difference. But I haven't been able to get that to work on your problem yet. I stared at... |
| Try something like eliminate {x,y} from {3x+4y+11z=9,2x-5y-3z=2,5x-4y+3z=11} which returns 11x= -18 My apologies for my mistake, that should have been 11z= -18 |
| Please check this very carefully to see if I have made any mistakes qe = 1.602176462 * 10^-19 ; (* elementary charge, C *); melectron = 9.10938188 * 10^-31 (* electron's mass, kg *); (* B0 = 0.9 remove that assignment to B0 so that... |
| F1[x_,y_]:=x*y F2[x_,y_]:=x/y G[x_,y_]:=x-y F[x_,y_]:=Which[G[x,y]>20,F1[x,y],G[x,y] |
| With the code above and a fresh start of Mathematica I get no error and blank plot. With the code above and a fresh start of Mathematica and z=1 I get no error and a good plot |
| There is a hidden cache of previous assignments that some users don't know about. Had you previously assigned any values or functions to any of those names? Try restarting Mathematica fresh, make certain you don't have any prior assignments ... |
| F[x_]:=Normal[Series[Exp[x],{x,0,2}]]; Plot[Evaluate[F[y]],{y,0,1}] >> |
| The best WolframAlpha method that I have been able to find is listcorrelate[{1.0, 1.25, 1.5, 1.75, 2.0, 2.25, 3.33},{1.0, 1.25, 1.5, 1.75, 2.0, 2.25, 3.33},1] What that appears to do is do the correlation between the two lists, shift/rotate... |
| If you carefully look at the documentation for Reduce you should see that it has Reduce[expression,thingToSolveFor,domain] In your Reduce above it thinks 0 |