Question 1045134
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what is the solution set for the 9x^4-8x^2-1=0
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{{{9x^4-8x^2-1}}} = {{{0}}}.

Factor the left side

{{{(9x^2+1)*(x^2-1)}}} = {{{0}}}.


The equation deploys in two independent equations


1.  {{{9x^2+1}}} = {{{0}}}.  It has no real solutions (it has complex solutions {{{x[1,2]}}} = +/-{{{(1/3)*i}}}, if you know complex numbers) 


2.  {{{x^2-1}}} = {{{0}}}.   It has two solutions  x = 1  and  x = -1.
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