_{}_{ }_{}_{} _{}

Symbol mathematics that is built-in in Mathcad
has one defect – it runs to limits: it *always *tries to give *all
answers* with absolute accuracy[1].
Because of it an expression that is ready for working with help of tools of
symbol mathematics, after carrying off the cursor (after order for execution
the command of symbol mathematics) becomes red. But it is the indication of
beginnings a mistake or additional specifying for user.

Such typical situation is showed in the fig. 95: user tries (point 1) to find roots of a
polynomial of fourth power. Two *tips* effluent the situation in point 1
in the fig. 95:

·
if an
operator of symbol transform has become red, then it does not mean yet that the
transform is possible: it is necessary to lead the cursor to the ablush
operator (but many users of Mathcad do not do it) and to read carefully the
error message;

·
when
you solve the problem with help of symbol mathematics it is worth to turn down
one of “the absolutes” (absolutely all answers with absolute accuracy): in
point 2 in the fig. 95 the additional operator float has allowed to find all solutions
in the form of decimal fraction but not with absolute accuracy (in the form of
analytical expression).

[1]
Calculus mathematics of
Mathcad is more “inclined
to compromise” – it
gives *one* answer
from many existent with *limited* accuracy.