tan(π/4+a)=(1+tana)/(1-tana)=2,
1+tana=2-2tana,
tana=1/3.
1/(2sinacosa+cos^2a)
=(sin^2a+cos^2a)/(2sinacosa+cos^2a)
=(tan^2a+1)/(2tana+1)
=(1/9+1)/(2/3+1)
=2/3.