(sinB-cosB)^2/sin^2B-cos^2B=3
(sinB-cosB)^2/(sinB-cosB)(sinB+cosB)=3
(sinB-cosB)/(sinB+cosB)=3
sinB-cosB=3sinB+3cosB
sinB=-2cosB
tanB=sinB/cosB=-2
(sinB-cosB)^2/sin^2B-cos^2B=3
(sinB-cosB)^2/(sinB-cosB)(sinB+cosB)=3
(sinB-cosB)/(sinB+cosB)=3
sinB-cosB=3sinB+3cosB
sinB=-2cosB
tanB=sinB/cosB=-2