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### Equation Solving, intersection of graphs [duplicate]

How can I find the points where these two graphs intersect: ContourPlot[{x == 1/2 (1 + Tanh[(x y^2)/0.5]),y == Tanh[(x^2 y)/0.5]}, {x, 0, 2}, {y, -1, 1}]
12k views

### How do I work with Root objects?

I want to solve the trigonometric equation : $$(3-\cos 4x )\cdot (\sin x - \cos x ) = 2.$$ I tried Solve[(3 - Cos[4*x])*(Sin[x] - Cos[x]) == 2, x] It returns the ...
8k views

### Can Reduce *really* not solve for x here?

Sometimes I get the feeling I'm just flailing blindly with Mathematica. Is solving for $x$ in the equation $$\frac{\cosh (x/2)}{x} = \sqrt{2}$$ really beyond the scope of Mathematica? I try to ...
1k views

### How do I solve this equation?

I want to solve the equation $$f(f(-1)) = \sqrt{2} + g(f(2)),$$ where $$f(x) = \dfrac{a}{x^2} - 3x + 2, \quad g(x) = a\cdot \sin 2x$$ $a$ is unknown. The solution is $a \approx{-5.81}$. I tried <...
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### Solve an equation in $\mathbb{R}^+$

How can I solve this equation (both numerically and literally) only in the positive reals $\mathbb{R}^+$? Solve[x == (v0 - (A CD t v0^2 ρ)/(4m)) Cos[θ] t, t] And ...
726 views

### How do I solve $1 - (1 - (A x)^2)^\frac{3}{2} - B(1 - \cos(x))= 0$?

Consider the equation $$1 - (1 - (A x)^2)^\frac{3}{2} - B(1 - \cos(x)) = 0$$ where $A,B \in \mathbb{R}$ are constants. What is the analytic solution?
962 views

### Is there a solution for this equation?

When I try to solve this equation using Mathematica: ...
437 views

### Solving an equation approximately

I have a complicated equation in terms of $\omega$ and $\kappa$: ...
511 views

### Why doesn't Roots work on a certain quartic polynomial equation?

Bug introduced in 9.0 or earlier and fixed in 10.0 In everything that follows I am using Roots to get the solutions to the equations. I start off with this ...
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### This system cannot be solved with the methods available to solve

I know questions about this warning have been posted a thousand times over. But I really couldn't find any solution that worked in my case. It's quite simple: ...
305 views

### Solve[ ] doesn't work with transcendental equations

How to solve x^5-sinx=0 in mathematica? I try in this way: Solve[x^5 - Sin[x] == 0, x],but t doesn't work.
343 views

### Can't solve equation having complex coefficients

Why can't Mathematica solve $\quad\quad\frac{1-i}{\sqrt{2}}=e^{i \alpha } \tan \left(\frac{\beta }{2}\right)$ with the restrictions $\alpha \in [0, 2 \, \pi)$ and $\beta \in [0,\pi]$: ...
426 views

### Finding and plotting a parametric solution to a complicated equation (transcendental, log-polynomial)

I am trying (desperately) to find a way to solve a transcendental equation whose solution $x$ depends on non-numerical parameters $a$ and $b$. And then to produce a ...