Question 1110251
2tan(x)/1+tan^2(x)=sin(2x)
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{{{2tan(x)/1+tan^2(x)=sin(2x)}}}
{{{2tan(x) + tan^2(x)=sin(2x)}}}
{{{2tan(pi/4) + tan^2(pi/4)=sin(pi/2)}}}
2 + 1 = 0
Not an identity.