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ranyai12
Group Title
Can someone please help!!! I keep getting it wrong!!!
Find the extreme values of
f(xy)=3x^2+2y^2−4x−3 on the region described as x^2+y^2 is less than or equal to 4
 one year ago
 one year ago
ranyai12 Group Title
Can someone please help!!! I keep getting it wrong!!! Find the extreme values of f(xy)=3x^2+2y^2−4x−3 on the region described as x^2+y^2 is less than or equal to 4
 one year ago
 one year ago

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harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
hey have you heard of langranges multipliers or not?
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
yea but i still got it wrong
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
ok so can you show the working ...
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
yea this is what i did: f_x=6x4<=4 6x<=8 x<=4/3 f_y=4y<=4 f_y<=1 fxx=6 fyy=4
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
and then i got stuck so i assumed the max was 6 and min was 1
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
but then i tried plugging in the values to the orginal equation and the number seemed wrong so idk what to do
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
firstly tell me that you want to proceed using concept of maxima minima using partial derivatives of langranges multipliers
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
is there an easier way
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
im good with anything
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
well perhaps i don`t think so because it`s gone in 2 dimension so lets do it by langranges multipliers 1. tell me what is gradient of f(x,y) ?
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
fx=6x4 fy=4y
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
so that is (6x 4)i + (4y)j tell me the same for the boundary x^2 + y^2 = 4 also?
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
im not sure im confused
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
fx=2x and fy=2y
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
so 2xi and 2yj
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
yes that is fine (2x)i + (2y)j so for extreme values to occur the gradient of the function and that of the boundary must be proportional so (6x 4)i + (4y)j = c((2x)i + (2y)j) now compare the i and j components and find the value of x and y in terms of c and tell me?
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
sry im not exactly sure what you mean
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
and whered the c come from
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
6x  4 = 2cx and 4y = 2cy c is the proportionality constant better say the extreme values occurs when the gradient of two is antiparallel or proportional
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
im sry im not sure what to do now
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
x = 4/(6  2c) and c = 2 from second equation so x = 2 not the boundary x^2 + y^2 = 4 putting x = 2 and finding out value of y which come out to be 0 so (2, 0) is the point of extreme value
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
so 2 is the max and 0 is the min
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
or do we plus in 2 into the equatio and thats hte max and 0 is the min
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
no the point (2, 0) will result in the extreme value of the function put x = 2 and y = 0 to yield the extreme value
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
but wouldnt that result in just one value and not max and min
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
yr supposed to find absolute max and min and i got the answer ot be 1 which is wrong
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
@harsimran_hs4 did you get 1 as well
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
yes perhaps then we screwed up with the calculation part can you tell me the answers if you have them with you?
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
the answers arent given :(
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
its an online hw thing
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
ok then why did you say it`s wrong?
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
because i plugged t in and it said it was wrong
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
ok let me figure out then and i`ll get back to you
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
ok thanks
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
can you plug in 3 and check if thats minimum value?
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
its not 3
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
do you get ve points if you put in a wrong answer if no then check out if 9 is maximum or not
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
i only have one more try left to find out what the max and min is
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
then wait...
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
you need to plug in both the values simultaneously or not?
 one year ago

ranyai12 Group TitleBest ResponseYou've already chosen the best response.0
yea but i can still get partial pints
 one year ago

harsimran_hs4 Group TitleBest ResponseYou've already chosen the best response.0
http://www.math.uri.edu/~bkaskosz/flashmo/graph3d/ check this this will give some insight to the problem but do link someone else also to this problem and figure out... i`ll try to get to some sure answer and then reply
 one year ago
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