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visits member for 2 years, 9 months
seen Dec 5 at 7:48

Nov
3
awarded  Tumbleweed
Oct
27
awarded  Teacher
Oct
27
answered Find the closed form of $\tan\frac{\pi }{64}$ by using the number $2$ only?
Oct
27
asked Noisy pencil of planes
Oct
11
revised Local maxima when multiplying two functions
added 39 characters in body
Oct
11
comment Local maxima when multiplying two functions
I see, yes that makes sense. So that question is, when do we find a "bump" in the product?
Oct
11
awarded  Commentator
Oct
11
comment Local maxima when multiplying two functions
sorry what do you mean by f|g?
Oct
11
revised Local maxima when multiplying two functions
restated the question more explicitly
Oct
11
comment Local maxima when multiplying two functions
sure, I'll try, let me know if I can clarify further - I'm still trying to formalise it properly in my head!
Oct
11
comment Local maxima when multiplying two functions
ok so this is definitely one right answer, but I don't think it covers all the possibilities. If for example $g(x)$ is a monotonically increasing/decreasing function in the neighbourhood of 0, then $f(0)g(0)$ should still give a local maximum, right?
Oct
11
asked Local maxima when multiplying two functions
Sep
27
awarded  Curious
Sep
26
accepted Proving maximum of dot product using derivatives
Sep
26
comment Proving maximum of dot product using derivatives
This is a really cool argument, thank you very much. In the same way I guess one could prove that for $a \cdot b$ to have a minimum, then $a′$ and $b$ must be parallel. It is a bit cyclical maybe since you need the notion that $a′ \cdot b$=0 for perpendicular vectors here, and $a′ \cdot b$=1 in the parallel case, but I really like the reasoning. One question though, why did you say in the beginning that the dot product is non-zero for non-zero b? Wouldn't it be zero for perpendicular vectors?
Sep
26
awarded  Informed
Sep
26
comment Proving maximum of dot product using derivatives
Sorry my mistake I am going to edit it now
Sep
26
asked Proving maximum of dot product using derivatives
Aug
27
accepted Number of sequences in a graph
Aug
27
revised Number of sequences in a graph
edited body