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Question-145202




Question Number 145202 by mnjuly1970 last updated on 03/Jul/21
Commented by loveineq last updated on 03/Jul/21
Wow, it likes a therom.
$$\mathrm{Wow},\:\mathrm{it}\:\mathrm{likes}\:\mathrm{a}\:\mathrm{therom}. \\ $$
Answered by ajfour last updated on 03/Jul/21
(x+3p)^2 +y^2 =a^2   (x+p)^2 +y^2 =b^2   (x−p)^2 +y^2 =c^2   (x+3p)^2 +y^2 =d^2   a^2 +3c^2 =4x^2 +12p^2 +4y^2   d^2 +3b^2 =4x^2 +12p^2 +4y^2   hence  a^2 +3c^2 =d^2 +3b^2
$$\left({x}+\mathrm{3}{p}\right)^{\mathrm{2}} +{y}^{\mathrm{2}} ={a}^{\mathrm{2}} \\ $$$$\left({x}+{p}\right)^{\mathrm{2}} +{y}^{\mathrm{2}} ={b}^{\mathrm{2}} \\ $$$$\left({x}−{p}\right)^{\mathrm{2}} +{y}^{\mathrm{2}} ={c}^{\mathrm{2}} \\ $$$$\left({x}+\mathrm{3}{p}\right)^{\mathrm{2}} +{y}^{\mathrm{2}} ={d}^{\mathrm{2}} \\ $$$${a}^{\mathrm{2}} +\mathrm{3}{c}^{\mathrm{2}} =\mathrm{4}{x}^{\mathrm{2}} +\mathrm{12}{p}^{\mathrm{2}} +\mathrm{4}{y}^{\mathrm{2}} \\ $$$${d}^{\mathrm{2}} +\mathrm{3}{b}^{\mathrm{2}} =\mathrm{4}{x}^{\mathrm{2}} +\mathrm{12}{p}^{\mathrm{2}} +\mathrm{4}{y}^{\mathrm{2}} \\ $$$${hence} \\ $$$${a}^{\mathrm{2}} +\mathrm{3}{c}^{\mathrm{2}} ={d}^{\mathrm{2}} +\mathrm{3}{b}^{\mathrm{2}} \\ $$
Commented by mnjuly1970 last updated on 03/Jul/21
thank you so much mr ajfor
$${thank}\:{you}\:{so}\:{much}\:{mr}\:{ajfor} \\ $$
Answered by mr W last updated on 03/Jul/21
((x^2 +b^2 −a^2 )/(2xb))=−((x^2 +b^2 −c^2 )/(2xb))  ⇒2x^2 =a^2 +c^2 −2b^2    ...(i)  similarly  ⇒2x^2 =b^2 +d^2 −2c^2    ...(ii)  a^2 +c^2 −2b^2 =b^2 +d^2 −2c^2   ⇒a^2 +3c^2 =d^2 +3b^2
$$\frac{{x}^{\mathrm{2}} +{b}^{\mathrm{2}} −{a}^{\mathrm{2}} }{\mathrm{2}{xb}}=−\frac{{x}^{\mathrm{2}} +{b}^{\mathrm{2}} −{c}^{\mathrm{2}} }{\mathrm{2}{xb}} \\ $$$$\Rightarrow\mathrm{2}{x}^{\mathrm{2}} ={a}^{\mathrm{2}} +{c}^{\mathrm{2}} −\mathrm{2}{b}^{\mathrm{2}} \:\:\:…\left({i}\right) \\ $$$${similarly} \\ $$$$\Rightarrow\mathrm{2}{x}^{\mathrm{2}} ={b}^{\mathrm{2}} +{d}^{\mathrm{2}} −\mathrm{2}{c}^{\mathrm{2}} \:\:\:…\left({ii}\right) \\ $$$${a}^{\mathrm{2}} +{c}^{\mathrm{2}} −\mathrm{2}{b}^{\mathrm{2}} ={b}^{\mathrm{2}} +{d}^{\mathrm{2}} −\mathrm{2}{c}^{\mathrm{2}} \\ $$$$\Rightarrow{a}^{\mathrm{2}} +\mathrm{3}{c}^{\mathrm{2}} ={d}^{\mathrm{2}} +\mathrm{3}{b}^{\mathrm{2}} \\ $$
Commented by mnjuly1970 last updated on 03/Jul/21
thank alot mr W , very nice    solution...
$${thank}\:{alot}\:{mr}\:{W}\:,\:{very}\:{nice}\: \\ $$$$\:{solution}… \\ $$

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