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arcticf0x
Group Title
Show that every point on the curve y=b sin (x/a), where the curve meets the axes of x, is a point of inflextion.
Do i have to plainly show that x=0 is a POI or its asking for something else?
 2 years ago
 2 years ago
arcticf0x Group Title
Show that every point on the curve y=b sin (x/a), where the curve meets the axes of x, is a point of inflextion. Do i have to plainly show that x=0 is a POI or its asking for something else?
 2 years ago
 2 years ago

This Question is Closed

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
inflection tends to be a found by a second derivative; and tested for cavage
 2 years ago

arcticf0x Group TitleBest ResponseYou've already chosen the best response.0
yeah i know that, but the language isnt very clear up there.
 2 years ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
looks like: b sin(x/a)/a^2 is the second derivative to me
 2 years ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
since b=0 is trivial; it looks to be what x/a = any mutiple of pi
 2 years ago

arcticf0x Group TitleBest ResponseYou've already chosen the best response.0
sorry didnt get that.
 2 years ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
how to "show" it? i aint got a clue
 2 years ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
sin(n*pi) = 0 so when x/a = n*pi we are at zero
 2 years ago

arcticf0x Group TitleBest ResponseYou've already chosen the best response.0
yeah thats where i came, so is that the answer fianlly, x=0
 2 years ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
x = a n*pi would seem to be the answer to me; but since n is an arbitrary integer then a*n would have to be an interger as well.
 2 years ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
other than that; I got no idea what the "answer" might entail ....
 2 years ago

arcticf0x Group TitleBest ResponseYou've already chosen the best response.0
umm, it says, where the curve meets the axes of x, so y=0 at that point, this only gives x=0.
 2 years ago

phi Group TitleBest ResponseYou've already chosen the best response.0
inflection point is where the second derivative changes sign. we know that y=b sin (x/a) crosses the xaxis when x/a is some multiple of 2pi the 2nd derivative at these same points is b sin(x/a)/a^2 = 0 also, if we go a dx distance below x/a and a little distance dx above x/a, the 2nd derivative changes sign. So we are at an inflection point.
 2 years ago

arcticf0x Group TitleBest ResponseYou've already chosen the best response.0
That seems clear, understood, thank you phi and amistre for your time :)
 2 years ago

phi Group TitleBest ResponseYou've already chosen the best response.0
*crosses the xaxis when x/a is some multiple of pi
 2 years ago
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