An ill-posed problem is a problem where the solution does not depend continuously on the data. This means that small changes in the input data can cause large changes in the final solution, making it difficult to find a stable or unique answer. Ill-posed problems are common in areas such as inverse problems and some types of optimization.

Such an equation would represent an ill-posed problem for all positive time (i.e. the solution is not defined). The irreversibility of diffusive processes is closely related to the second law of thermodynamics.

Petr

The teacher posed the math problem 5 plus 11 and 1/2. I had a problem figuring out the math problem.

The first route posed the problem of not being able to get through.

V. A. Morozov has written:

'Regularization methods for ill-posed problems' -- subject(s): Differential equations, Partial, Improperly posed problems, Partial Differential equations

'Methods for solving incorrectly posed problems' -- subject(s): Differential equations, Partial, Improperly posed problems, Partial Differential equations