A reason that cannot be used to justify a statement in a proof is an unsupported assumption or opinion. For example, stating that "because I believe it's true" lacks empirical or logical backing and does not adhere to the standards of formal reasoning. Proofs require verifiable evidence, established theorems, or axioms, rather than personal beliefs or unsubstantiated claims.
Since you didn't include the statements in your question there is no way for us to know
In a proof, statements that are purely opinion-based or subjective, such as personal beliefs or interpretations, cannot be used to justify steps. Additionally, unsupported assertions that lack logical reasoning or empirical evidence, as well as circular reasoning where the conclusion is included in one of the premises, are also invalid. Lastly, statements that are not universally accepted or established laws, such as conjectures that have not been proven, cannot justify proof steps.
Logically invalid statements.
Yes. That is what theorems are for. Once proven, their results do not need to be justified again (except for exams).
Mathematical logic.
Since you didn't include the statements in your question there is no way for us to know
conclusion
yes
In a proof, statements that are purely opinion-based or subjective, such as personal beliefs or interpretations, cannot be used to justify steps. Additionally, unsupported assertions that lack logical reasoning or empirical evidence, as well as circular reasoning where the conclusion is included in one of the premises, are also invalid. Lastly, statements that are not universally accepted or established laws, such as conjectures that have not been proven, cannot justify proof steps.
There cannot be a proof because the statement is not true.nowhere does the statement say
guess and conjeture
Guess Conjecture
Yeah
Logically invalid statements.
Theorems, definitions, corollaries, and postulates
corresponding angles
AAA (angle angle angle) cannot be used as a reason in a proof when proving triangles congruent .