(1+tanx)/(1-tanx)=2
1+tanx=2-2tanx
tanx=1/3
cosx^2=1/(1+tanx^2)=1/(10/9)=9/10
cosx^2+3sinxcosx+2sinx^2=1+3tanxcosx^2+(1-cosx^2)=1+3*(1/3)*(9/10)+(1-9/10)=2
(1+tanx)/(1-tanx)=2
1+tanx=2-2tanx
tanx=1/3
cosx^2=1/(1+tanx^2)=1/(10/9)=9/10
cosx^2+3sinxcosx+2sinx^2=1+3tanxcosx^2+(1-cosx^2)=1+3*(1/3)*(9/10)+(1-9/10)=2