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x-x-x-1-1-x-1-1-x-4-find-x-




Question Number 131430 by mathlove last updated on 04/Feb/21
(((((x^x )^x ))^(1/(1/x)) ))^(1/(1/x)) =4       find  x=?
(xx)x1x1x=4findx=?
Commented by math35 last updated on 04/Feb/21
((((x^x^2  )^(1/(1/x)) ))^(1/(1/x)) =4  note:(y)^(1/(1/n)) =y^(1/(((1/n)))) =y^n   →  (((x^x^2  )^x ))^(1/(1/x)) =4       (x^x^3  )^x =4        x^x^4  =4  taking ln of both sides  x^4 lnx=ln4  e^(lnx^4 ) .lnx=ln4  e^(4lnx) .4lnx=4ln4  e^(4lnx) .4lnx=e^(ln4) .ln4  taking lambert W function of both sides  W[e^(4lnx) .4lnx]=W[e^(ln4) .ln4]  4lnx=ln4  lnx=(1/4)ln2^2 =(2/4)ln2  lnx=(1/2)ln2  lnx=ln(√2)  x=(√2)
(xx21x1x=4note:y1n=y1(1n)=yn(xx2)x1x=4(xx3)x=4xx4=4takinglnofbothsidesx4lnx=ln4elnx4.lnx=ln4e4lnx.4lnx=4ln4e4lnx.4lnx=eln4.ln4takinglambertWfunctionofbothsidesW[e4lnx.4lnx]=W[eln4.ln4]4lnx=ln4lnx=14ln22=24ln2lnx=12ln2lnx=ln2x=2
Commented by mathlove last updated on 05/Feb/21
what is the W function?
whatistheWfunction?
Answered by talminator2856791 last updated on 04/Feb/21
 x = 4
x=4
Commented by mathlove last updated on 04/Feb/21
pleas solve
pleassolve
Answered by mr W last updated on 05/Feb/21
i interpret the question as:  ((((x^x )^(1/(1/x)) )^x ))^(1/(1/x)) =4  ⇔((((x^x )^x )^x ))^(1/(1/x)) =4  ⇔(((x^x )^x )^x )^x =4  ⇔((x^x^2  )^x )^x =4  ⇔(x^x^3  )^x =4  ⇔x^x^4  =4  ⇒x^4 =4  ⇒x=(4)^(1/4) =(√2)>0
iinterpretthequestionas:(xx1x)x1x=4((xx)x)x1x=4(((xx)x)x)x=4((xx2)x)x=4(xx3)x=4xx4=4x4=4x=44=2>0
Commented by mathlove last updated on 05/Feb/21
thanks a lot sir
thanksalotsir
Commented by mr W last updated on 05/Feb/21
x^x^x^⋰^x^a     = a  has the same solution as x^a =a,  i.e. x=(a)^(1/a)
xxx\iddotsxa=ahasthesamesolutionasxa=a,i.e.x=aa
Commented by Tawa11 last updated on 23/Jul/21
great
great