(6cos^4x-sin^2x-1)/(2(2cos^2x -1))怎么化简

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/04 09:32:14
(6cos^4x-sin^2x-1)/(2(2cos^2x -1))怎么化简

(6cos^4x-sin^2x-1)/(2(2cos^2x -1))怎么化简
(6cos^4x-sin^2x-1)/(2(2cos^2x -1))怎么化简

(6cos^4x-sin^2x-1)/(2(2cos^2x -1))怎么化简
(6cos^4x-sin^2x-1)/[2(2cos^2x -1)]
=(6cos^4 x + cos²x -2) /2(2cos^2x -1)]
=[(3cos²x+2)(2cos²x-1)]/2(2cos^2x -1)]
=(3cos²x+2)/2
=(3/2)*cos²x +1