Precalculus books: why answers only for odds?

[den99]

Hello, why in all precalculus books are only odd numbers to answers ? where is even numbers ? How should i know if the answer is correct ? Thx.

[stapel_eliz]

Hello, why in all precalculus books are only odd numbers to answers ? where is even numbers ? How should i know if the answer is correct ? Thx.

I think it's just become the custom. There's no "rule". But if all the answers were provided, how would instructors be able to tell if you'd found any of the answers yourself?

If you're wanting more practice but want the answers, try doing all the odds, rather than just the ones assigned.

[den99]

well i'm doing it all on my own, os there is no teacher who would tell me even answers thx for answer.