已知(tgA+1)/(1-tgA)=3+2根号2 求sinA和cosA

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已知(tgA+1)/(1-tgA)=3+2根号2求sinA和cosA已知(tgA+1)/(1-tgA)=3+2根号2求sinA和cosA已知(tgA+1)/(1-tgA)=3+2根号2求sinA和co

已知(tgA+1)/(1-tgA)=3+2根号2 求sinA和cosA
已知(tgA+1)/(1-tgA)=3+2根号2 求sinA和cosA

已知(tgA+1)/(1-tgA)=3+2根号2 求sinA和cosA
(tgA+1)/(1-tgA)=3+2根号2
=>tgA+1=(3+2根号2)*(1-tgA)
=>tgA+1=3-3tgA+2根号2-2根号2tgA
=>2tgA+2根号2tgA=2+2根号2
=>(2+2根号2)tgA=2+2根号2
=>tgA=1
即sinA=cosA
sinA=cosA=(根号2)/2