Question Number 141924 by Study last updated on 24/May/21
$${cos}\left({x}−\mathrm{180}\right)=? \\ $$
Commented by MJS_new last updated on 24/May/21
$$−\mathrm{cos}\:{x} \\ $$
Answered by mathmax by abdo last updated on 24/May/21
$$−\mathrm{cosx} \\ $$