Tip 77. Vector of solutions
from Find-function
In the fig. 75 two solutions of
the problem about “Nautilus” differ not only the way of writing the equations
forming the solvable system (siplification – complication), but also the method of call the function Find, that returns the solution of the problem. In the first case
(simplified
formulas) the function Find is inputted in the output operator “=”[1],
but in
the second case (complication of the formulas) – in the input operator “:=”. In the fig. 75 the choice of way of call the
function Find have not had an
influence on search of the result but in the example of the tip 77 – way of call the
function has an influence very much.
In the fig. 77 the function Find returns not only one but a set of solutions (a matrix). For it is necessary to put down the value of a range (Range variable – “dummy vector”[2]) but not scalar value in one of three constants (first approximation: in our case it is d – diameter of the submarine). This method is described in the Mathcad documentation but for the problem with one unknown. Point is that this method can be used if we insert the function Find into the operator “=”. The operator “:=” gives the bug here. Obviously it is concerned with that the solution is a Nested Array – vector which elements are new vectors. In the fig. 77 the transposition operator of a matrix and the function of horizontal mating of a matrix (augment) are used in addition for formatting the result. All these allowed to obtain the result as a tabular with the commentaries in a “hat” where there are explanations. It is possible draw a graph by the tabular data but we do it another way (in the tip 78).