sinA+cosA=√10/5二边平方得:1+2sinAcosA=2/5sinAcosA=-3/101/sinA+1/cosA=(cosA+sinA)/(sinAcosA)=(√10/5)/(-3/10)=-2√10 /3根据sin^2A+cos^2A=1,二边同除以sinAcosA,得tanA+1/tanA=1/(sinAcosA)=-10/3tan^2A+1=-...