Menu Close

x-abc-1-4-x-abc-1-8-a-x-abc-1-4-x-abc-1-8-b-x-abc-1-4-x-abc-1-4-c-find-x-abc-x-abc-




Question Number 161065 by cortano last updated on 11/Dec/21
  { ((((x+abc))^(1/4)  +((x−abc))^(1/8)  = a)),((((x+abc))^(1/4)  −((x−abc))^(1/8)  = b)),((((x+abc))^(1/4)  −((x−abc))^(1/4)  = c)) :}   find (√(x+abc)) +(√(x−abc))
$$\:\begin{cases}{\sqrt[{\mathrm{4}}]{{x}+{abc}}\:+\sqrt[{\mathrm{8}}]{{x}−{abc}}\:=\:{a}}\\{\sqrt[{\mathrm{4}}]{{x}+{abc}}\:−\sqrt[{\mathrm{8}}]{{x}−{abc}}\:=\:{b}}\\{\sqrt[{\mathrm{4}}]{{x}+{abc}}\:−\sqrt[{\mathrm{4}}]{{x}−{abc}}\:=\:{c}}\end{cases} \\ $$$$\:{find}\:\sqrt{{x}+{abc}}\:+\sqrt{{x}−{abc}} \\ $$
Answered by Rasheed.Sindhi last updated on 12/Dec/21
  { ((((x+abc))^(1/4)  +((x−abc))^(1/8)  = a....(i))),((((x+abc))^(1/4)  −((x−abc))^(1/8)  = b.....(ii))),((((x+abc))^(1/4)  −((x−abc))^(1/4)  = c.....(iii))) :}  2((x+abc))^(1/4)  =a+b  ((x+abc))^(1/4)  =((a+b)/2)  (((x+abc))^(1/4)  )^2 =(((a+b)/2))^2   (√(x+abc)) =(((a+b)/2))^2 ...........A  2((x−abc))^(1/8)  =a−b  ((x−abc))^(1/8)  =((a−b)/2)  (((x−abc))^(1/8)  )^4 =(((a−b)/2))^4   (√(x−abc)) =(((a−b)/2))^4 .........B  A+B: (√(x+abc)) +(√(x−abc))                         =(((a+b)/2))^2 +(((a−b)/2))^4   Without using (iii) !!!
$$\:\begin{cases}{\sqrt[{\mathrm{4}}]{{x}+{abc}}\:+\sqrt[{\mathrm{8}}]{{x}−{abc}}\:=\:{a}….\left({i}\right)}\\{\sqrt[{\mathrm{4}}]{{x}+{abc}}\:−\sqrt[{\mathrm{8}}]{{x}−{abc}}\:=\:{b}…..\left({ii}\right)}\\{\sqrt[{\mathrm{4}}]{{x}+{abc}}\:−\sqrt[{\mathrm{4}}]{{x}−{abc}}\:=\:{c}…..\left({iii}\right)}\end{cases} \\ $$$$\mathrm{2}\sqrt[{\mathrm{4}}]{{x}+{abc}}\:={a}+{b} \\ $$$$\sqrt[{\mathrm{4}}]{{x}+{abc}}\:=\frac{{a}+{b}}{\mathrm{2}} \\ $$$$\left(\sqrt[{\mathrm{4}}]{{x}+{abc}}\:\right)^{\mathrm{2}} =\left(\frac{{a}+{b}}{\mathrm{2}}\right)^{\mathrm{2}} \\ $$$$\sqrt{{x}+{abc}}\:=\left(\frac{{a}+{b}}{\mathrm{2}}\right)^{\mathrm{2}} ………..{A} \\ $$$$\mathrm{2}\sqrt[{\mathrm{8}}]{{x}−{abc}}\:={a}−{b} \\ $$$$\sqrt[{\mathrm{8}}]{{x}−{abc}}\:=\frac{{a}−{b}}{\mathrm{2}} \\ $$$$\left(\sqrt[{\mathrm{8}}]{{x}−{abc}}\:\right)^{\mathrm{4}} =\left(\frac{{a}−{b}}{\mathrm{2}}\right)^{\mathrm{4}} \\ $$$$\sqrt{{x}−{abc}}\:=\left(\frac{{a}−{b}}{\mathrm{2}}\right)^{\mathrm{4}} ………{B} \\ $$$${A}+{B}:\:\sqrt{{x}+{abc}}\:+\sqrt{{x}−{abc}}\: \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:=\left(\frac{{a}+{b}}{\mathrm{2}}\right)^{\mathrm{2}} +\left(\frac{{a}−{b}}{\mathrm{2}}\right)^{\mathrm{4}} \\ $$$${Without}\:{using}\:\left({iii}\right)\:!!! \\ $$

Leave a Reply

Your email address will not be published. Required fields are marked *