(1)tan(π/4 +α)=1/2[tan(π/4) +tanα]/[1-tan(π/4)tanα] =1/2(1 +tanα)/(1-tanα) =1/22(1 +tanα)=1-tanα3tanα = -1tanα =-1/3(2)(sin2α-(cosα)^2)/(1+cos2α)=(2sinαcosα-(cosα)^2)/(2(cosα)^2)=(2...