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I've a problem with the function Simplify. I've this equations x^2 + 2 x + 1 == 0 and 4 x^2 == 0. If I use Simplify, it returns 1 + x == 0 and x == 0. How I can force Simplify to not simplify this type of equations? I've to use Simplify in a function and I need it for other cases.

Thanks

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    $\begingroup$ The question is not clear. A good idea would be to show the expression with Simplify to let us see what is it that you are after. $\endgroup$ – Alexei Boulbitch May 11 '16 at 11:19
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You can use the ExcludeForms option described in the Simplify documentation.

For example,

Simplify[{x^2 + 2 x + 1 == 0, 4 x^2 == 0}, ExcludedForms -> {0}]

(* returns {(x + 1)^2 == 0, 4 x^2 == 0} *)

Alternatively,

Simplify[{x^2 + 2 x + 1 == 0, 4 x^2 == 0}, ExcludedForms -> {x^2, 0}]

(* returns {1 + 2 x + x^2 == 0, 4 x^2 == 0} *)

The actual forms to exclude will depend a bit on what your other expressions look like, but you can find a few more general pattern examples in the ExcludedForms documentation.

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  • $\begingroup$ And if I have 3 (2 - 6 x) == 9 (3 - 2 x) - 21, how I force Simplify to not show True but simply 0 == 0? $\endgroup$ – RossFe May 19 '16 at 13:26
  • $\begingroup$ @RossFe, Sorry but I am not sure I understand the question. Is x define to a set value? Or do you want both the constants and x variable dominate from both sides? Out of curiosity, why do you prefer 0==0 over True? $\endgroup$ – Rashid May 19 '16 at 13:57

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