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q-a-a-9-1-108-a-3-1-3-1-3-b-b-9-1-108-b-3-1-3-1-3-a-9-37-72-b-9-37-72-find-q-correct-to-5-decimal-places-




Question Number 157046 by ajfour last updated on 18/Oct/21
q={a+((a/9)−(1/(108))−a^3 )^(1/3) }^(1/3)     +{b+((b/9)−(1/(108))−b^3 )^(1/3) }^(1/3)      a=((9+(√(37)))/(72))   ,  b=((9−(√(37)))/(72))   find q correct to 5 decimal   places.
$${q}=\left\{{a}+\left(\frac{{a}}{\mathrm{9}}−\frac{\mathrm{1}}{\mathrm{108}}−{a}^{\mathrm{3}} \right)^{\mathrm{1}/\mathrm{3}} \right\}^{\mathrm{1}/\mathrm{3}} \\ $$$$\:\:+\left\{{b}+\left(\frac{{b}}{\mathrm{9}}−\frac{\mathrm{1}}{\mathrm{108}}−{b}^{\mathrm{3}} \right)^{\mathrm{1}/\mathrm{3}} \right\}^{\mathrm{1}/\mathrm{3}} \\ $$$$\:\:\:{a}=\frac{\mathrm{9}+\sqrt{\mathrm{37}}}{\mathrm{72}}\:\:\:,\:\:{b}=\frac{\mathrm{9}−\sqrt{\mathrm{37}}}{\mathrm{72}} \\ $$$$\:{find}\:\boldsymbol{{q}}\:{correct}\:{to}\:\mathrm{5}\:{decimal} \\ $$$$\:{places}. \\ $$
Commented by ajfour last updated on 18/Oct/21
could it be an answer to  x^3 −x=(1/4)   ?
$${could}\:{it}\:{be}\:{an}\:{answer}\:{to} \\ $$$${x}^{\mathrm{3}} −{x}=\frac{\mathrm{1}}{\mathrm{4}}\:\:\:? \\ $$

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