已知4sin^a-3sinacosa-5cos^a=1,则tana=

已知4sin^a-3sinacosa-5cos^a=1,则tana=
已知4sin^a-3sinacosa-5cos^a=1,则tana=

已知4sin^a-3sinacosa-5cos^a=1,则tana=
4sin^a-3sinacosa-5cos^a=sin^a+cos^a
3sin^a-3sinacosa-6cos^a=0
同时除以cos^a
3tan^a-3tana-6=0
tan^a-tana-2=0
(tana-2)(tana+1)=0
tana=2或者tana=-1