# what is the purpose of “as” here?

Use the Pythagorean Theorem to find the missing side, being careful to mark the value as positive or negative as makes sense in that quadrant.

I simply cannot understand how, grammatically, "as" is used in that sentence. Is it used as a relative pronoun? I'm simply lost. Please help!

• @Catija Thank you! It's not some mathematical term. It's just usual as. – ohgodpleasegod Jun 9 '16 at 19:23
• It's the same as in "as you please" or "do X as you would do Y." You could replace it with "in the manner in which" but it's rather less concise :-). – phoog Jun 9 '16 at 20:06

I don't have the documentation to support my answer, but if it helps I believe there is an implied pronoun:

Use the Pythagorean Theorem to find the missing side, being careful to mark the value as positive or negative as it makes sense in that quadrant.

It's similar to saying something like, "please stand as able" for a ceremony, implying "please stand as you are able," which contains not only an implied pronoun but an implied verb.

• Thank you! But I don't understand why this "it" should have been elided. Does it sound unnatural with "it"? Is that why? – ohgodpleasegod Jun 9 '16 at 20:14
• I agree the omission makes the sentence more awkward, but I've seen the omission in formal publications like textbooks as well as signage before. – Gracie Jun 9 '16 at 20:20

It's being used as a conjunction, and it seems most similar to this definition

Used to indicate by comparison the way that something happens or is done:
they can do as they wish
she kissed him goodbye, as usual

In your quote, it actually means something more like whichever.

• So this second "as" (..."as" makes sense) is not related to the first "as" (value "as" positive or negative) at all, am I correct? Also, what is the noun that is implied or deleted? Is it "as it makes sense? – ohgodpleasegod Jun 9 '16 at 20:12
• Yes, that's correct. The implied noun is the result of deciding between positive and negative, or the process of deciding. – Barmar Jun 9 '16 at 20:15
• I really appreciate it. But just one more question. Why is it elided? Does it sound better when elided? – ohgodpleasegod Jun 9 '16 at 20:19
• Because restating it would be redundant. You already said to make the decision, this is just describing the reason for the decision. – Barmar Jun 9 '16 at 20:20

It is being used as a conjunction in this case to indicate the reason or time for doing something. In this case, it is a subordinating conjunction with the clause: