Question 799489
compute sqrt ((cosx-sinx)^2 + (sinx+cosx)^2) 
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((cosx-sinx)^2 + (sinx+cosx)^2)
{{{cos^2(x)-2sin(x)cos(x)+sin^2(x)+cos^2(x)+2sin(x)cos(x)+sin^2(x)}}}
{{{cos^2(x)+sin^2(x)+cos^2(x)+sin^2(x)=1+1=2}}}