若tan(x-π)=2,求2sin^2x+1/cos^2x-sin^2x的值若tan(x-π)=2,求2sin^2x+1/cos^2x-sin^2x的值
问题描述:
若tan(x-π)=2,求2sin^2x+1/cos^2x-sin^2x的值
若tan(x-π)=2,求2sin^2x+1/cos^2x-sin^2x的值
答
tan(x-π)=tanx=22sin²x+1/cos²x-sin²x=2sin²x+sin²x+cos²x/cosx²x-sin²x=3sin²x+cos²x/cos²x-sin²x=[(3sin²x/cos²x)+(cos²x/cos²...