请数学高手解题,送财富

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请数学高手解题,送财富

请数学高手解题,送财富
请数学高手解题,送财富

 

请数学高手解题,送财富

两边同时乘以cosx(1-sinx)
得(cosx)^2=1-(sinx)^2
(sinx)^2+(cosx)^2=1 得证
或者(sinx)^2+(cosx)^2=1
(cosx)^2=1-(sinx)^2=(1+sinx)(1-sinx)
两边同时除以以cosx(1-sinx)
得题目

左边=(cos^2x/2-sin^2x/2)/(cosx/2-sinx/2)^2
=(cosx/2+sinx/2)(cosx/2-sinx/2)/(cosx/2-sinx/2)^2
=(cosx/2+sinx/2)/(cosx/2-sinx/2)
=(1+tanx/2)/(1-tanx/2)
=tan(x/2+π/4)
右边=(cosx/2+sinx/2)^...

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左边=(cos^2x/2-sin^2x/2)/(cosx/2-sinx/2)^2
=(cosx/2+sinx/2)(cosx/2-sinx/2)/(cosx/2-sinx/2)^2
=(cosx/2+sinx/2)/(cosx/2-sinx/2)
=(1+tanx/2)/(1-tanx/2)
=tan(x/2+π/4)
右边=(cosx/2+sinx/2)^2/(cos^2x/2-sin^2x/2)
=(cosx/2+sinx/2)^2/(cosx/2+sinx/2)(cosx/2-sinx/2)
=(cosx/2+sinx/2)/(cosx/2-sinx/2)
=(1+tanx/2)/(1-tanx/2)
=tan(x/2+π/4)
左边=右边

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