( cos(x) + sin(x) ) * [ tan(x) + cot(x) ]
( cos(x) + sin(x) ) * [ sin(x)/cos(x) + cos(x)/sin(x) ]
( cos(x) + sin(x) ) * [ sin(x)*sin(x)/cos(x)*sin(x) + cos(x)*cos(x)/sin(x)*cos(x) ]
( cos(x) + sin(x) ) * [ sin^2(x)/cos(x)*sin(x) + cos^2(x)/sin(x)*cos(x) ]
( cos(x) + sin(x) ) * [ ( sin^2(x) + cos^2(x) ) / sin(x)*cos(x) ]
( cos(x) + sin(x) ) * [ (1/ sin(x)*cos(x) ]
[ ( cos(x) + sin(x) ) / sin(x)cos(x) ]
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3)
tan(x) * (1 - cot^2(x)) + cot(x) * (1 - tan^2(x))
tan(x) - cot^2(x) * tan(x) + cot(x) - tan^2(x) * cot(x)
sin(x)/cos(x) - ( cos^2(x)/sin^2(x) )*( sin(x)/cos(x) )+ cos(x)/sin(x)- (sin^2(x) / cos^2(x)) * cos(x)/sin(x)
sin(x)/cos(x) - ( cos(x)/sin(x) ) + cos(x)/sin(x) - (sin(x) / cos(x))
sin(x)/cos(x) - (sin(x) / cos(x))
0