解:sinx=2cosx∴tanx=2∴sin�0�5x+1=(2sin�0�5x+cos�0�5x)/(sin�0�5x+cos�0�5)分号两边同除以cos�0�5x=(2tan�0�5x+1)/(tan�0�5x+1)=(2×2�0�5+1)/(2�0�5+1)=9/5
∵sinx=2cosx ∴tanx=sinx/cosx=2sin�0�5x+1=(sin�0�5x+1)/1=(sin�0�5x+sin�0�5x+cos�0�5x)/(sin�0�5x+cos�0�5x)分式上下同除cos�0�5x得sin�0�5x+1=(2tan�0�5x+1)/(tan�0�5x+1)=9/5
tanx=2(sin^2 x+sin^2 x +cos^2 x)/(sin^2 x +cos^2 x)=同时除以COS^2 X得:(tan^2 x+tan^2 x+1)/(tan^2 x+1)带入tanx=2得原式等于(4+4+1)/(4+1)=9/5