(2/3sin^2a-sinacosa+cos^2a)/cos^2a*cos^2a
=(2/3tan^2a-tana+1)*cos^2a
=5cos^2a/3
tana=2
sina/cosa=2
sin^2a/cos^2a=4
(1-cos^2a)/cos^2a=4
cos^2a=1/5
(2/3sin^2a-sinacosa+cos^2a)/cos^2a*cos^2a
=(2/3tan^2a-tana+1)*cos^2a
=5cos^2a/3
=1/3
(2/3sin^2a-sinacosa+cos^2a)/cos^2a*cos^2a
=(2/3tan^2a-tana+1)*cos^2a
=5cos^2a/3
tana=2
sina/cosa=2
sin^2a/cos^2a=4
(1-cos^2a)/cos^2a=4
cos^2a=1/5
(2/3sin^2a-sinacosa+cos^2a)/cos^2a*cos^2a
=(2/3tan^2a-tana+1)*cos^2a
=5cos^2a/3
=1/3