Linked Questions

0
votes
1answer
139 views

Reduce in NDSolve [duplicate]

Second order ode; neither the trig RHS simplifies nor is the solution obtained readily: ...
1
vote
0answers
68 views

DSolve throws an error about Solve and returns unevaluated [duplicate]

I evaluate: DSolve[{2*y[x] + y'[x]^2 + a*x^b == 0}, y[x], x] During evaluation of In[26]:= Solve::ifun: Inverse functions are being used by Solve, so some ...
0
votes
0answers
28 views

How to understand the results of solve:ifun? [duplicate]

I am trying to obtain an analytical solution of the following equation: My goal is to express \rho in terms of all other parameters (analytically solve RR function), so what is the result that ...
12
votes
3answers
1k views

Trying to find the asymptote to a function

I am trying to find the asymptote to a solution of a differential equation. I solved $x'(t) = \sin(x(t) + t)$ using NDSolve and plotted my solution. ...
7
votes
2answers
1k views

DSolve misses a solution of a differential equation

[Note that in the cited duplicate, DSolve not finding solution I expected, the general solution returned by DSolve is missing a solution for quite different reasons ...
3
votes
4answers
492 views

Coupled linear time-varying system of differential equations. Analytical solution?

How to solve the system analytically in the interval {to,t} ...
4
votes
3answers
565 views

Why does DSolve return two solutions for my ODE?

I wanted to solve the differential equation: $y’ = (1+2x)\sqrt{y}$ with $y(0) = 1$. It can be done by hand, and to check my answer I typed the following in Mathematica ...
7
votes
2answers
203 views

Unexpected warning from DSolve

I'm trying to solve this differential equation with respect to $x$ $$ \frac{d^2y}{dx^2}-\bigg(\frac{dy}{dx}\bigg)^2-\frac{1}{x}\frac{dy}{dx}=\frac{1}{x^2} $$ With boundary condition $y(1)=2, y'(1)=-...
7
votes
1answer
523 views

DSolve with SetOptions[Solve, Method -> Reduce] Behaving Differently in Ver 11.1.1

With version "11.1.1 for Microsoft Windows (64-bit) (April 18, 2017)", DSolve[{SI'[s] == Sin[PH[s]] , PH'[s] == Sin[SI[s]]/e}, {SI[s], PH[s]}, s] produces the ...
4
votes
1answer
550 views

Ordinary differential equation invloving the function composition

I want to solve the following function: DSolve[(A1*Exp[B1*f[x]] + A2*Exp[B2*f[x]])*f'[x] == A1*Exp[B1*x] + A2*Exp[B2*x], f[x], x] And this is what I get as an ...
0
votes
1answer
251 views

Result interpretation of a general solution of a nonlinear differential equation

My goal is to find the general solution of the following nonlinear differential equation: $$x'(t) = e^{-t} - \sqrt{x(t)}$$ Following this guide, I've entered in the Wolfram Mathematica the following ...
1
vote
0answers
85 views

Differential equation, Inverse Functions being used and a way to bypass it.

I have the following differential equation ...
1
vote
0answers
77 views

Controlling precision/accuracy inside built-in commands

Some functions (such as Erf) appear to use NIntegrate internally. In such cases, is there a way to control such options of ...