Question

tg(пи/4-a), если tg(a)=3

Answer 1

tg(x-y)=(tgx-tgy)/(1+tgx*tgy)
tg(pi/4-a)=(tgpi/4 - tga)/(1+tgpi/4*tga)
tgpi/4=1;
tg(pi/4-a)=(1-3)/(1+1*3)=-2/4=-1/2