cos^2 x - 2sinxcosx - sin^2 x = 0 [ 0 ≤2x≤ pi ]cos^2 x - 2sinxcosx - sin^2 x = 0 [ 0 ≤2x≤ pi ]

来源:学生作业帮助网 编辑:六六作业网 时间:2024/05/24 01:41:31
cos^2x-2sinxcosx-sin^2x=0[0≤2x≤pi]cos^2x-2sinxcosx-sin^2x=0[0≤2x≤pi]cos^2x-2sinxcosx-sin^2x=0[0≤2x≤p

cos^2 x - 2sinxcosx - sin^2 x = 0 [ 0 ≤2x≤ pi ]cos^2 x - 2sinxcosx - sin^2 x = 0 [ 0 ≤2x≤ pi ]
cos^2 x - 2sinxcosx - sin^2 x = 0 [ 0 ≤2x≤ pi ]
cos^2 x - 2sinxcosx - sin^2 x = 0 [ 0 ≤2x≤ pi ]

cos^2 x - 2sinxcosx - sin^2 x = 0 [ 0 ≤2x≤ pi ]cos^2 x - 2sinxcosx - sin^2 x = 0 [ 0 ≤2x≤ pi ]
原式=cos2x-sin2x=2^(1/2)*cos(2x+pi/4)=0,因为0