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Let-go-toward-a-rational-order-of-derivation-Part-1-What-s-that-special-factor-Let-n-p-and-k-three-integer-different-of-zero-We-state-J-n-k-p-0-1-1-x-n-p-k-n-dx-and-C-n-




Question Number 65828 by ~ À ® @ 237 ~ last updated on 04/Aug/19
 Let go toward a rational order of derivation    Part 1 :  What′s that special factor    Let n , p and k three integer  different of zero  We  state J_(n,k) (p)=∫_0 ^1   (1−x^n )^(p+(k/n)) dx   and  C_n (p)=Π_(k=0) ^(n−1)  J_(n,k) (p)  1) a) Calculate C_1 (p)        b) Prove that  J_(n,k) (p)=(1/n)B((1/n),p+1+(k/n) )   and  explicit  C_n (p)in terms of  n and p   2) Deduce that ∀ n>0    there exist a real a_n  such as  (na_n )^n C_n (p)= (1/(p+1))   3) Study the convergence of the result suite (a_n )_n    .Then show that lim_(n−>∞)  na_n  =1  Part 2:  the rational order of derivation  Let  f ∈ C^1 (R,R) . We  consider I_(1/n) (f) a function defined on R_+  by     I_(1/n) (f)(x)= a_n ∫_0 ^x   ((f(t))/((x−t)^(1−(1/n)) ))dt       and  D_(1/n) (f) = (I_(1/n) (f))^((1))     1) a _  Prove that I_((1/n) ) (f)(x)= na_n x^(1/n)  ∫_0 ^1   f(x(1−v^n ))dv   then find D_(1/2) (t)    b)  Show that  ∀ f∈C^1 (R,R) ∀ x∈R_(+  )  D_(1/n) (f)(x)= I_(1/n) (f)(x)  + ((f(0))/((πx)^(1−(1/n)) ))  2)∀ p integer and  k∈{0,...,n−1}  explicit  I_(1/n) (t^(p+(k/n)) ) in term of  I_(n,k) (p)  b) Prove that for polynomial function f   the n− th composition  I_(1/n) ._ ....I_(1/n) (f)(x)=∫_0 ^x f(t)dt     ,     c) Deduce that ∀  f  polynomial  the function g =f −f(0) verify  D_(1/n) ......D_(1/n) (g)(x) = g(x)  3) Widen that two formulas to all  function that can be developp into integer serie  4) Try to find the relation between  D_(1/n) .I_(1/n) (f) ,  I_(1/n) .D_(1/n) (f), and  f    4) Show  that ∀ x∈R_+   lim_(n−>∞)   I_(1/n) (f)(x)= ∫_0 ^x  f(t)dt         pour  g=f−f(0)   lim_(n−>∞)   D_(1/n) (g)(x)= g(x)  conclusion   the derivative of the function I_α  (f)  defined on R_+   by   I_α (f)(x)= a_n ∫_0 ^x  f(t)(x−t)^((1/n)−1) dt  is  called the  derivative of order α
LetgotowardarationalorderofderivationPart1:WhatsthatspecialfactorLetn,pandkthreeintegerdifferentofzeroWestateJn,k(p)=01(1xn)p+kndxandCn(p)=n1k=0Jn,k(p)1)a)CalculateC1(p)b)ProvethatJn,k(p)=1nB(1n,p+1+kn)andexplicitCn(p)intermsofnandp2)Deducethatn>0thereexistarealansuchas(nan)nCn(p)=1p+13)Studytheconvergenceoftheresultsuite(an)n.Thenshowthatlimn>nan=1Part2:therationalorderofderivationLetfC1(R,R).WeconsiderI1n(f)afunctiondefinedonR+byI1n(f)(x)=an0xf(t)(xt)11ndtandD1n(f)=(I1n(f))(1)1)a_ProvethatI1n(f)(x)=nanx1n01f(x(1vn))dvthenfindD12(t)b)ShowthatfC1(R,R)xR+D1n(f)(x)=I1n(f)(x)+f(0)(πx)11n2)pintegerandk{0,,n1}explicitI1n(tp+kn)intermofIn,k(p)b)ProvethatforpolynomialfunctionfthenthcompositionI1n..I1n(f)(x)=0xf(t)dt,c)Deducethatfpolynomialthefunctiong=ff(0)verifyD1nD1n(g)(x)=g(x)3)Widenthattwoformulastoallfunctionthatcanbedeveloppintointegerserie4)TrytofindtherelationbetweenD1n.I1n(f),I1n.D1n(f),andf4)ShowthatxR+limn>I1n(f)(x)=0xf(t)dtpourg=ff(0)limn>D1n(g)(x)=g(x)conclusionthederivativeofthefunctionIα(f)definedonR+byIα(f)(x)=an0xf(t)(xt)1n1dtiscalledthederivativeoforderα
Commented by ~ À ® @ 237 ~ last updated on 04/Aug/19
   I_α (f)(x)=a_n ∫_0 ^x   f(t)(x−t)^(α−1) dt
Iα(f)(x)=an0xf(t)(xt)α1dt