Tip 27. Trust but verify


Fig. 27. Trust but verify

Certainly this tip concerns not only to Mathcad but also to all software for solution of mathematical problems. So if you get an answer, don’t be lazy to verify it. The roots of our system (see tip 24 and tip 26) are substituted in the initial equations in the fig. 27. For it the matrix with the roots from Mathcad-document, which illustrates tip 26, is put down in the variable Roots. Then the pairs of values from lines of the matrix Roots are carried to the variables x and y. In their turns they are substituted in left parts of the algebraic equations of the test system. It is possible to predetermine about quality of the solution using the analysis of residual (it equals 5.627.10-4 for six root).