Найдите значение выражения tg(3Pi/8)*tg(Pi/8)+1
tg(3π/8)·tg(π/8)=(sin(3π/8)·sin(π/8))/(cos(3π/8)·cos(π/8))= =(1/2)(cos(2π/8)-cos(4π/8))/(1/2)(cos(4π/8)+cos(2π/8)) Так как cos(4π/8)=cos(π/2)=0, cos(2π/8)=cos(π/4), то tg(3π/8)·tg(π/8)+1= =cos(π/4)/cos(π/4)+1=2 О т в е т. 2