# Tag Info

3

I received a prompt response from Wolfram Technical Support: "...there is an option in system setting called 'AssumptionsMaxNonlinearVariables'. This option specifies the maximal number of variables in non-linear inequality assumptions. By default, this option is set as 4. After changing it to 5, the issue is solved" ...

3

Here is a simple answer Define k[n] as a listable function : SetAttributes[k, Listable] k[n_] := \!$$\*SubsuperscriptBox[\(\[Integral]$$, $$3$$, $$10$$]$$\*FractionBox[\(1 + Cos[f\ \((1 + 2\ n\ )$$\ \[Pi]]\), $$1 + Cos[f\ \[Pi]]$$] \[DifferentialD]f\)\) then define a list compose of integer of the desired Length --- say 10 nn = Range[10] ask ...

1

Guessing OP meant f1*f2 == f1*f3 == f1* f4 == f1*f5 == f2*f3 == f2*f4 == f2*f5 == f3*f4 == f3*f5== f4*f5 ==0, matrix = {{f1, -f2, -f2, f3}, {f4, -f1, -f1, f2}, {f4, -f1, -f1, f2}, {f5, -f4, -f4, f1}}; assumptions = Thread[(Subsets[Times[f1, f2, f3, f4, f5], {2}]) == 0]; ToRadicals @ FullSimplify[Eigensystem[matrix], Assumptions -> assumptions]

5

As I somehow forgot but Szabolcs reminded me many System variables (typically with names beginning with $) check the values they are set to, e.g.:$MinPrecision := -6 $MinPrecision \$MinPrecision::precset: Cannot set \$MinPrecision to -6; value must be a non-negative number or Infinity. >> 0 In this case the check causes evaluation you do not ... 4 To change the assumptions dynamically, this can be used:$Assumptions := b b = {c > 0}; Refine[{c < 0, c == 0, c > 0}] b = {c < 0}; Refine[{c < 0, c == 0, c > 0}] If you need to evaluate the Print every time, this can be used: \$Assumptions := Evaluate[b] b = {c > 0, Unevaluated@Print[kount]}; kount = 1; Refine[{c < 0, c == 0, c > 0}] kount = 2; ...

2

I think what you mean is Assuming[a<0 && b\[Element]Reals && c==3, FullSimplify[Integrate[f[a,b,c,d], {d,e,f}]]] if you have different assumptions for different variables, or with the same assumption for a bunch of variables: Assuming[{a, b, c}>0 && a>b, FullSimplify[Integrate[f[a,b,c,d], {d,e,f}]]] so use the ...

3

You can use a conditional replacement rule to set any power of x higher than 1 to zero: simp[expr_, x_] := ExpandAll[expr] /. {Power[x, a_] /; a > 1 -> 0} simp[(1/x - 3 x + 4 - x)^4, x] simp[(1 - x)^2, x] (* -416 + 1/x^4 + 16/x^3 + 80/x^2 + 64/x - 256 x *) (* 1 - 2 x *) Of course, the easy way to do it would be to just take the Series and convert ...

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