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f-x-3-x-1-f-x-3-1-x-x-find-f-x-




Question Number 87755 by john santu last updated on 06/Apr/20
f(((x−3)/(x+1))) + f(((x+3)/(1−x))) = x  find f(x)
f(x3x+1)+f(x+31x)=xfindf(x)
Commented by john santu last updated on 06/Apr/20
(i) let ((x−3)/(x+1)) = x′ ⇒f(x′) + f(((x′−3)/(x′+1))) = ((x′+3)/(1−x))  (ii) let ((x+3)/(1−x)) = x′⇒ f(((x′+3)/(1−x′))) +f(x′) = ((x′−3)/(x′+1))  eq +(i)+(ii)  2 [ f(((x−3)/(x+1)))+f(((x+3)/(1−x)))+f(x) ] = x+((x+3)/(1−x))+((x−3)/(x+1))  2 [ x +f(x) ] = ((x(1−x^2 )+x^2 +4x+3−x^2 +4x−3)/(1−x^2 ))  2 [ x+f(x) ] = ((−x^3 +9x)/(1−x^2 ))  f(x) = ((9x−x^3 )/(2−2x^2 )) − ((x(2−2x^2 ))/(2−2x^2 ))  f(x) = ((x^3 +7x)/(2−2x^2 )) .
(i)letx3x+1=xf(x)+f(x3x+1)=x+31x(ii)letx+31x=xf(x+31x)+f(x)=x3x+1eq+(i)+(ii)2[f(x3x+1)+f(x+31x)+f(x)]=x+x+31x+x3x+12[x+f(x)]=x(1x2)+x2+4x+3x2+4x31x22[x+f(x)]=x3+9x1x2f(x)=9xx322x2x(22x2)22x2f(x)=x3+7x22x2.
Commented by jagoll last updated on 06/Apr/20
thank you mister. ilike  this question
thankyoumister.ilikethisquestion

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