Question 1012337
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{{{6cos^2(x)-3}}} = {{{0}}}  -----> 

{{{cos^2(x)}}} = {{{3/6}}} = {{{1/2}}}  ----->

cos(x) = +/- {{{sqrt(2)/2}}}.

Thus the original equation deployed in two equations:


1. cos(x) = {{{sqrt(2)/2}}}  ----->  The solutions in the given interval are x = {{{pi/4}}}  and  x = {{{7pi/4}}}.


2. cos(x) = {{{-sqrt(2)/2}}}  -----> The solutions in the given interval are x = {{{3pi/4}}}  and  x = {{{5pi/4}}}.


<U>Answer</U>. x = {{{pi/4}}}, {{{3pi/4}}}, {{{5pi/4}}} and {{{7pi/4}}}.
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