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SciMax Toolbox >> zeroequiv

zeroequiv

Maxima Function

Calling Sequence

zeroequiv (expr, v)

Description

Tests whether the expression expr in the variable v is equivalent to zero, returning true, false, or dontknow.

zeroequiv has these restrictions:

  1. Do not use functions that Maxima does not know how to differentiate and evaluate.

  2. If the expression has poles on the real line, there may be errors in the result (but this is unlikely to occur).

  3. If the expression contains functions which are not solutions to first order differential equations (e.g. Bessel functions) there may be incorrect results.

  4. The algorithm uses evaluation at randomly chosen points for carefully selected subexpressions. This is always a somewhat hazardous business, although the algorithm tries to minimize the potential for error.

For example zeroequiv (sin(2*x) - 2*sin(x)*cos(x), x) returns true and zeroequiv (%e^x + x, x) returns false. On the other hand zeroequiv (log(a*b) - log(a) - log(b), a) returns dontknow because of the presence of an extra parameter b.

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