已知M属于RA大于B大于1

已知A属于(0,pai2),B属于(0,pai) sinA cosB=-86...

sinA cosB=-865(sinA cosB)^2=（-865）^2(sinA)^2 (cosB)^2 2sinAcosB=(8/65)^2 (1)sin（A B）=-3365 sinA*cosB sinB*cosA=-33/65sinB cosA =K(sinB cosA)^2 =K^2(sinB)^2 (cosA)^2 2sinBcosA=K^2 (2)(1) (2):[(sinA)^2 (cosB)^2 2sinAcosB] [(sinB)^2 (cosA)^2 2sinBcosA]=(8/65)^2 K^2[(sinA)^2 (cosB)^2 (sinB)^2 (cosA)^2...全部

  sinA cosB=-865(sinA cosB)^2=（-865）^2(sinA)^2 (cosB)^2 2sinAcosB=(8/65)^2 (1)sin（A B）=-3365 sinA*cosB sinB*cosA=-33/65sinB cosA =K(sinB cosA)^2 =K^2(sinB)^2 (cosA)^2 2sinBcosA=K^2 (2)(1) (2):[(sinA)^2 (cosB)^2 2sinAcosB] [(sinB)^2 (cosA)^2 2sinBcosA]=(8/65)^2 K^2[(sinA)^2 (cosB)^2 (sinB)^2 (cosA)^2] 2(sinA*cosB sinB*cosA)=(8/65)^2 K^22 2*(-33/65)=(8/65)^2 K^2K^2=64/65-64/65^2K^2=64/65(1-1/65)K^2=64/65*64/65A属于(0,pai2),B属于(0,pai)sinB>0 cosA>0sinB cosA =K>0K^2=(64/65)^2K=64/65sinB cosA =K=64/65。
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