Which term describes the process of reaching a conclusion that is necessarily true based on given assumptions?

The term that describes the process of reaching a conclusion that is necessarily true based on given assumptions is deducing. Deduction is a logical reasoning process where a specific conclusion is drawn from general principles or premises. This method ensures that if the premises are true, the conclusion must also be true, making it a valid form of reasoning commonly used in mathematics and formal logic.

Defining involves clarifying the meaning of a term or concept rather than drawing a conclusion. Determining relates to establishing or figuring something out, which may not necessarily involve a logical conclusion strictly based on premises. Demonstrating involves providing evidence or proof to support a conclusion but does not specifically relate to the logical structure of reaching a necessarily true conclusion from assumptions. Thus, deducing is the most accurate term for this process.