hi to all members i am new here hehe tuesday my school started and i have homework to do for tommorow plz help
soit s un nombre reel donne.parmi tous lescouples(alfa,beta) de nb reels dont la somme est s,quel est celui dont le produit p=alfa.beta maximum ??
it's french but plz help!!!
lol tnx mate for the traslation and for this results tnx alot
my second probleme??
One has access to four carees of respective a,a+1,a+2,a+3. quotations can one to choose has for that the air of the biggest one be
egale has the sum of the others
plz help now
P a number reel donne.parmi all the couples (esparto, beta) of number reels of which produced it is p,quel the one of which the sum s = esparto + beta is minimum?
help me 2 hours and my class started
Lets assume that this is telling us that we have four crates of similar form
with charateristic dimensions a, a+1, a+2, a+3. The largest has a volume
equal to the sum of the volumes of the other three, find a.
The volumes are proportional to the cube of the charateristic dimension, so:
(a+3)^3=a^3 + (a+1)^3 + (a+2)^3.
This simplifies after expanding the cubes to:
2a^3 - 12a -18 = 0.
Which has a single real solution of a=3.
RonL
Of all pairs of real numbers (alpha, beta) with product equal to p (best
assume p>0 here), find that pair for which their sum s is a minimum.
alpha.beta=p,
so
beta=p/alpha.
Hence:
s=alpha+beta=alpha+p/alpha.
The minimum (if it exists) of s occurs when ds/d(alpha)=0
ds/d(alpha)=1 - p/alpha^2
So the alpha we are interested in is a root of:
alpha^2 - p=0,
or alpha=+/- sqrt(p)
You probably want alpha and beta to be >=0, in which case the positive root is
what you want, also you should justify that this is in fact a minimum.
RonL