[x0x0]

figure out in the sense of discover? sure

Figure out in the sense of work out the updates, particularly for f:R -> R, if you already understand NR? That's totally doable in 5 minutes with paper; it's just figuring out an x intercept. And remembering/finding f such that f(sqrt(2)) = 0

I've also been asked, in person, the derivative of x^x. Hope you remember logarithmic differentiation! It's not like, had you happened to not have used this trick for a derivative in the last 10+ years, you could look up and recall in 5 minutes given you understand chain rule. I remembered it, but what kind of filter is this?

[kafkaesq]

"Discover" in the sense of "derive ab initio, truly never having seen an iterative root-finding method, or anything analogous to it" -- like Newton and Raphson both did, separately -- I highly doubt it.

Re-derive your (or my) perhaps-more-than-a-bit-stale-by-this-point derivation, from way back when, under non-interview conditions? Yeah sure -- assuming we were actual math majors, or among the 10% or of CS majors who are burned-in math types.

But under interview conditions? Unless the role explicitly requires an actual math background (or a CS background with emphasis in numerical algorithms), really quite a silly thing to expect of someone.

[x0x0]

oops -- when I said "figure out in the sense of discover? Sure" I was unclear, but I agree -- that request would be ludicrous.

That said, I have full faith that Gauss would pass that interview. Probably Euler, Tao, Dantzig, and Turing too =P

But it's not entirely unreasonable for optimization/OR/ML people. Mostly they have to remember how to construct the right function to find the zero of. Most applications of NR just want to find the zeroes of gradients of loss functions.

I certainly am not disputing the silliness... I personally am not good at math at a whiteboard while someone is staring at me. And full disclosure: I remember NR from the picture -- the x intercept of the tangent is (hopefully) closer to the zero than the initial guess.

[kafkaesq]

If these companies would just say, in their job descriptions, that that's the calibre of people they need to debug their glorified hotel booking website (or whatever), then that would make things much simpler for everyone:

"When we say we're looking for the next Norvig or Knuth for this role, we mean it -- and you'll be tested accordingly!"

[x0x0]

How could you debug a crud app if you're not Knuth?

Makes no sense.