∵tanα=-2∴cosα≠0(1)原式=(cosα+3sinα)/(3cosα-sinα)=[(cosα+3sinα)×1/cosα]/[(3cosα-sinα)×1/cosα]=(1+3sinα/cosα)/(3-sinα/cosα)=(1+3tanα)/(3-tanα)=[1+3×(-2)]/(3+2)=-1(2) ∵sin²...