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Mathematics 9 Online
OpenStudy (jlrich):

Which of the following is an identity? CHECK ALL THAT APPLY. A. tan(x-pi)= tanx B. sin(x+y) -sin(x-y)= 2cosxsiny C. cos(x+y) +cos(x-y)= 2cosxcosy D. cos(x+y)-cos(x-y)=2cosxcosy

OpenStudy (witty_roger):

c

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