Question 334159
{{{sin(x)=-1/3}}}
{{{sin(x)^2+cos(x)^2=1}}}
{{{(1/9)+cos(x)^2=1}}}
{{{cos(x)^2=1-1/9}}}
{{{cos(x)^2=8/9}}}
{{{cos(x)=-(2sqrt(2))/3}}}
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{{{sin(2x)=2sin(x)cos(x)}}}
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{{{sin(2x)=2(-1/3)(-(2sqrt(2))/3)}}}
{{{highlight(sin(2x)=(4sqrt(2))/9)}}}
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{{{sin(2x)^2+cos(2x)^2=1}}}
{{{32/81+cos(2x)^2=1}}}
{{{cos(2x)^2=1-32/81}}}
{{{cos(2x)^2=49/81}}}
{{{highlight(cos(2x)=7/9)}}}