ТРИГОНОМЕТРИЧЕСКИЕ ФУНКЦИИ ЧИСЛОВОГО АРГУМЕНТА.
1.(sint+cost)²/(1+2sintcost)=(sint+cost)²/sin²t+cos²t+2sintcost)= =(sint+cost)²/(sint+cost)²=1 2. (1-2sintcost)/(cost-sint)²=(cos²t+sin²t-2costsint)/(cost-sint)²=(cost-sint)²/(cost-sint)²=1