Final answer:
In propositional logic, the expression "If x = 4, then y = -2" is represented by 'p → q', where 'p: x = 4' and 'q: y = -2'.
Step-by-step explanation:
The expression that represents "If x = 4, then y = −2" is formulated using propositional logic. In this case, the statement "If x = 4" is represented by p, and the statement "then y = −2" is represented by q.
Therefore, the logical connector that we need to use to express "if p, then q" is known as the implication or conditional, and is typically represented using the → symbol. So, the expression that represents "If x = 4, then y = −2" is p → q.