Answer:
(n∨k) ∧ ¬(n∧k)
Explanation:
We use three symbols, remember that
p∧q is true if and only if p is true and q is true
p∨q is true if and only if p is true or q is true
¬p is true if and only if p is false.
Now, to represent the statement "Either this polynomial has degree 2 or it has degree 3 but not both", the part "Either this polynomial has degree 2 or it has degree 3" can be written as "n∨k". The word "but" translates into "∧", and ""not both", means "not n∧k", that is, "¬(n∧k)". Hence the final proposition is (n∨k) ∧ ¬(n∧k)