Skip to main content
Mathematica
Bob Hanlon's user avatar
Bob Hanlon's user avatar
Bob Hanlon's user avatar
Bob Hanlon
  • Member for 10 years, 10 months
  • Last seen this week
  • Clarksville, MD
Profile Activity

12,284 Actions

All Accepts Posts Badges Comments Revisions Reviews Suggestions
comment
How to Determine When to Switch to Arbitrary-Precision Values?
See Numbers
comment
Mathematica does not accept that this variable is a positive real?
A list is automatically converted, e.g., look at {Rin, L1, C2, L3, Rout} \[Element] PositiveReals // FullForm
comment
Why does Replace function not work the first time I try it?
I don't know why it doesn't work, but you can use ReplaceRepeated (//.) instead of ReplaceAll (/.)
comment
Why does FindInstance[x>0,x] give 27?
Because as Options[FindInstance] shows, the default RandomSeeding is 1234
comment
How to use these many conditions inside product?
@yarchik - As you indicated, it is not clear what was intended. You are free to interpret the intent as you wish.
answered
How can we verify the accuracy of options B, C, and D in this multiple-choice question using alternative methods?
comment
Checking whether a linear homogeneous system with m equations and n>m unknowns, has m unknowns that are sums with positive coefficients of the others
Your rv does not consists solely of variables. Some elements are products of variables. Do you want the products treated as if they were single variables or rather split into the separate variables?
answered
How to use these many conditions inside product?
comment
Is the output for ConvexHullRegion wrong in Mathematica 13.3?
Under the Help menu, use Give Feedback ...
comment
How to find the solutions to simulteneous linear equations in mathematica, in case if the solution to them is not unique?
@yarchik - It was documented in V7 (perhaps earlier?). See reference.wolfram.com/legacy/v7/ref/Solve.html While no longer documented, it still works. You can emulate this by also using Eliminate
comment
How to find the solutions to simulteneous linear equations in mathematica, in case if the solution to them is not unique?
Or Solve[{b + c - a - d == 0, 2 b - a + c == 0, c - e == 0}, {b, d}, {c}] or Solve[{b + c - a - d == 0, 2 b - a + c == 0, c - e == 0}, {b, d}, MaxExtraConditions -> 1]
comment
Confused about the output of `CosIntegral`
See Entity["MathematicalFunction", "CosIntegral"]["Dataset"]
comment
How can I use the values of one plot in another one?
r /. Solve[..., r] is equivalent to SolveValues[..., r]
answered
How can I use the values of one plot in another one?
comment
How can I use the values of one plot in another one?
Please provide a concrete example of what you are trying to do and show what you have tried.
comment
Why is NDsolve plot returning an empty plot?
With NDSolve the answer is zero to some level of precision. With DSolve the answer is shown to be exactly zero.
comment
Summation not returning a timely result
Reversing the order of the summation also works here:F1 = Simplify[Sum[16^j/(4 + 16^j), {j, a, b, c}] /. {a -> 1/2025, b -> 2024/2025, c -> 1/2025}]; F2 = Simplify[Sum[16^j/(4 + 16^j), {j, b, a, -c}] /. {a -> 1/2025, b -> 2024/2025, c -> 1/2025}]; (F1 + F2)/2 // FullSimplify
comment
Why is NDsolve plot returning an empty plot?
Or look at sol = DSolve[{y''[x] - 2*y[x] == 0, y'[-1] == 0, y'[1] == 0}, y[x], x]
comment
Solving and plotting roots of a non polynomial equation with parameters
Those options provide more stable operation of the Manipulate.
comment
Summation not returning a timely result
After using N you can use Rationalize to get the exact result.
1
2 3 4 5
…
615