Why don't you have a try at convincing him?

为什么你不试试说服他？

《牛津词典》

He saw a trainer nearby and asked why these animals just stood there and didn't try to get away.

他看到附近有个驯兽师，就问为什么这些动物只是站在那里，而不试图逃跑。

youdao

If you have lots of things and have nowhere to put them, and don't want to throw them away, why not try a car boot sale?

如果你有很多东西，但又没有地方放，又不想扔掉，为什么不尝试一下旧货市场呢？

youdao

So let's go to a second clicker question here and try one more. So why don't you tell me how many possible orbitals you can have in a single atom that have the following two quantum numbers?

让我们来看下一道题目,你们来告诉我,有多少个可能的轨道,含有这些量子数呢？

麻省理工公开课 - 化学原理课程节选

and got a couple of compliments on my pictures, so figured, "Why not try this?"

然后照片受了点表扬，我就想“干嘛不试试这一行呢？”

拍照的理由 - SpeakingMax英语口语达人

And there's a lot of significance in that, I think, and I'll try to explain why.

我认为这一点至关重要，我会告诉你们原因。

耶鲁公开课 - 文学理论导论课程节选

Why the Kremlin would do such a thing, why it would try to make a thoroughly discredited Yeltin-era hack who has for the past decade led a rapidly revolving carousel of small (and short-lived) anti-Kremlin parties into an increasingly sympathetic poster child for the opposition, is not readily apparent.

FORBES: Leave Boris Nemtsov Alone. Leave Him Alone!

If you are looking for a template for averting and managing future banking messes, why not try a touch of Hayek for Cyprus and for Europe for that matter?

FORBES: Cyprus Has, In Effect, Moved Out Of The Eurozone Roach Motel

Why not try a new approach, if only as an experiment?

ECONOMIST: Shopping for a drugs policy