Question

What can be used as a reason in a two-column proof?

Select each correct answer.

A. a property of algebra

B. a counterexample

C. a given

D. a conjecture

Answer 1

@Vocaloid

Answer 2

any thoughts?
hint: given and properties are facts by nature, so if they help you achieve your conclusion, they should be used.

Answer 3

a property of algebra

a conjecture

a given.

Answer 4

not sure if a conjecture counts...

(i would get a second opinion because it's been way too long since i've done proofs lol)

Answer 5

Oh hey, well I think the best answer here would be "a property of algebra"
A counterexample could be used in some proofs, but it wouldn't really make sense in the context of proving that something is true.
A given would be more like the starting point of the proof, not one of the steps.
And conjecture is more or less guessing, so that definitely doesn't have any place here.

Answer 6

Aww, thanks for the medal > <;;

Answer 7

Hey, it's always nice to see participation on the site :)

Answer 8

I think the question allows for multiple answers, though :o

Answer 9

Hm, in that case, I guess I'd better think again.
I guess a 'given' could also be interpreted as something that logically follows from something else. So, in that sense, it would make sense in a two-column proof.
I still think the other two should be excluded.