Упростить 5sinП/2-4ctg3П/2+3cosП

5*1 -4*0 +3 * (-1) = 5-0-3 = 2 ------------------------------------------------------------------------   cos ²α * 1\ cos²α = 1 --------------------------------------------------------------------------- tg α = 1 \ ctg α tg α = 1 : (-9\40) = - 40\9 = - 4 4\9 ----------------------------------------------------------------------------