Asking for help is really the best answer, but here's a little more that may be useful.
So for those who have been in industry
for any longer length of time, what
would happen if you were told to solve
a problem that you couldn't? Has it
happened, and if so, what did happen?
Did they just drop it and said "Oh
well, guess we can make do with
something else"? Were there
consequences? Were you reprimanded, or
Yes, it's happened to me, and no, I never got reprimanded or fired for it, because...
In industry, it's all about whether you solve problems on time and within budget, and decent managers understand that's not always possible.
What really happens is your manager says, "I'd like you to do X, what do you think it will take?" And you can give lots of answers. Good ones include:
- I've done something really similar to this, so I think it will take three weeks and $3,000 worth of testing hardware.
- I've something generally similar to this. So let me think about it and get back to you this afternoon.
- I've never done anything like this. So let me research it and get back to you tomorrow.
- Nobody on the planet has ever done this. If you want to look into it, it will take me two weeks to do enough experimentation to make an estimate.
It's the manager's job to decide whether and how to proceed. If they do choose to proceed, it's your job to meet your estimates, or let the manager know if there's an impediment. As long as you do that, in a reasonable company there won't be negative consequences.
Of course, there are also unreasonable companies that don't give you the time or resources to get your job done. I've worked at some of those, and everybody was handed problems that couldn't be solved within the company's constraints. One of them laid off about 98% of the programming staff within eight months, and that certainly was a consequence, but it wasn't personally directed at me, and I still consider my boss and his boss from there to be good friends.