# Tag Info

### Is it possible to have Mathematica move all terms to one side of an inequality?

Since Mathematica 11.3 you can use SubtractSides, that works for equations and inequalities, for example ...
• 36.5k
Accepted

### Reduce not making full use of list of assumptions?

What I believe is the issue here is what a statement in your Reduce like c ∈ Reals actually means. You say it's a condition (and ...
• 65.8k

### What does {x,y}<0 mean?

Generally, this is an invalid use of <. Both the left and the right-hand side should be expressions representing real numbers. However, there are a few special ...
• 235k
Accepted

### What does {x,y}<0 mean?

From the documentation: Less gives True or False when its arguments are real numbers. ...
• 9,458

### Calculating the width of the interval defined by an inequality

f[ineq_, var_] := RegionMeasure[ImplicitRegion[ineq, var], Length[Flatten[{var}]]] f[1 <= x <= 2.5, x] 1.5 This works also for some systems of ...
Accepted

### Calculating union of two sets of reals

You can try Reduce[{-(1/4) < x <= 0 || 0 < x <= 1/2 || x > 1/2}, x] x > -(1/4) ...
• 1,032

### Checking inequalities: How can $x>0,y>0$ yet $x+y$ indeterminate?

The assumptions mechanism used by Simplify has a bound on the number of variables in a system of nonlinear inequalities. If the number of variables exceeds the bound, the assumption mechanism does not ...
• 3,510
Accepted

### Can Mathematica solve $|-x\cdot\exp(-0.5x^2/b^2)/b^2|<0.01$?

If we want exact values we should work with them from scratch. eq[t_, x_] := Abs[-x Exp[-1/2 x^2/(t^2)]/(t^2)] The boundary of the set of our interest can be ...
• 57.3k
Accepted

### Make Reduce produce nicer output

If you are OK with turning the Ors into Columns, you can do something like: ...
• 11.2k

### How can I test if two inequalities have a common part?

Does a value of x which fulfils both conditions exist? ...
• 19.1k
Accepted

### Relational operators on vectors

And @@ Thread[{a, b} > {c, d}] (* a > c && b > d *)
• 116k
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### Summation with inequalities

n = 5; Sum[1/r[j, k]^α, {k, 1, n}, {j, 1, k - 1}] r[1, 2]^-α + r[1, 3]^-α + r[1, 4]^-α + r[1, 5]^-α + r[2, 3]^-α + r[2, 4]^-α + r[2, 5]^-α + r[3, 4]^-α + ...
• 395k
Accepted

### Solve for parameters so that a relation is always satisfied

What do you prefer: ...
• 26.4k
Accepted

### Why isn't this expression returning true to being positive when it is clearly positive?

Simplify is at root an expression tree minimizer, equipped with some algebraic and logical transformations. As such, it may have the transformations needed to reach ...
• 236k
Accepted

### Why does MMA fail to find a solution but WA does?

First, my stab at W|A gave a different output than the OP (something like what I show for Reduce below, in fact). Second, I'm not sure how to read the W|A output ...
• 236k
Accepted

• 66.2k
Accepted

### Strange behavior with Inequality and pattern matching

The issue is pre-evaluation of the pattern. For the ones that evaluate to False: Inequality[___] (* True *) and ...
• 23.5k

### Restrictions on variables of two functions in order to be larger and smaller relative to each other

re = Reduce[f1[x, y] < f2[x, y], {x, y}, Reals] Reduce[f1[x, y] > f2[x, y], {x, y}, Reals] ...
• 25.8k

### Volume of a 3D implicit region

I think the main issue is the axes bounds are quite disproportionate and that's effecting the sampling. Here's your region scaled to the unit cube: ...
• 36k
Accepted

### Isolate variable in inequality

Try Reduce[Abs[2 - x] > 2, x, Reals] (*x < 0 || x > 4*)
• 53.9k

### Can't this inequality really not be solved with Reduce?

We can change variable. f[n_, a_] = n + a*ProductLog[-E^(-n/a)]; f[n, a] <= 1 /. n -> t*a // Simplify ...
• 72.9k

...
• 54k
Accepted

### Reduce a complex inequality

First of all you shouldn't (if possible) use approximate numbers working with symbolic functionality like a very sophisticated function Reduce. Before seeking the ...
• 57.3k
Accepted

### Problems with integrating over a region

You need to be consistent with the order of the variables defining the region: ...
Accepted

### Ask Mathematica if there exists a value that satisfies conditions

Mainly just to see how Reduce@Exists[..] stacks up against FindInstance[]. I suspect the heuristics of ...
• 236k

### Strange behavior with Inequality and pattern matching

Inactivate is helpful in analyzing this problem. ...
• 108k
Accepted

### Restrictions on variables of two functions in order to be larger and smaller relative to each other

By trial and error, if we plot Plot3D[{f1[x, y], f2[x, y]}, {x, -2, 2}, {y, -2, 2}] we see that x== 1-y^2 is the ...
• 23k
Accepted

### How to solve $n\left(\frac{n}{n+1}\right)^n>1$ for $n\in\Bbb N$?

Reduce works like a charm: Reduce[x*(x/(1 + x))^x > 1 && x > 0, x, Integers] x ∈ Integers && x >= 3
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### Get the inequalities from answers

First of all I get five solutions for your system from Solve: ...
• 272k