tan(4/π-α)=3-tana=tan(-a)=tan[(4/π-α)-4/π]=[tan(4/π-α)-tan(4/π)]/[1+tan(4/π-α) * tan(4/π)]=(3-1)/(1+3)=1/2;tana=-1/2sin2a=(2tana)/[1+(tana)^2]=-4/5cos2a=[1-(tana)^2]/[1+(tana)^2]=3/5sin2α-...