tanA=2 求(sin^2 A+ sinAcosA)/(tanA+1+sin^2 A) 急 .

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tanA=2 求(sin^2 A+ sinAcosA)/(tanA+1+sin^2 A) 急 .

tanA=2 求(sin^2 A+ sinAcosA)/(tanA+1+sin^2 A) 急 .
tanA=2 求(sin^2 A+ sinAcosA)/(tanA+1+sin^2 A) 急 .

tanA=2 求(sin^2 A+ sinAcosA)/(tanA+1+sin^2 A) 急 .
∵tanA=2
∴sin2A=2tanA/(1+tan^2 A)=4/5
cos2A=(1-tan^2 A)/(1+tan^2 A)=-3/5
∴原式=[(1-cos2A)/2+sin2A/2]/(tanA+3/2-cos2A/2)
=6/19

(sin^2 A+ sinAcosA)/(tanA+1+sin^2 A)
=(tan^2 A+ tanA)/[ (1+tan^2 A)(tanA+1+sin^2 A) ]
=(4+2)/[ (1+4)*(2+1+4/5)
=6/(5*3.8)
=6/19