化简1-cos^4a-sin^4a/1-cos^6-sin^6acos^6应为cos^6a

来源：学生作业帮助网编辑：作业帮时间：2024/11/06 07:28:58

化简1-cos^4a-sin^4a/1-cos^6-sin^6acos^6应为cos^6a
化简1-cos^4a-sin^4a/1-cos^6-sin^6a
cos^6应为cos^6a

化简1-cos^4a-sin^4a/1-cos^6-sin^6acos^6应为cos^6a
1-cos^6-sin^6a=1-(sin^2+cos^a)(cos^4a-cos^2asin^2a+sin^4a)=1-cos^4a+cos^2asin^2a-sin^2a
=3cos^2asin^2a
1-cos^4a-sin^4a=cos^2a-cos^4a+sin^2a-cos^4a=2cos^2asin^a
原式=2/3

首先。题大概有点问题
1> (1-cos^4a-sin^4a)/(1-cos^6-sin^6a)
没打括号。不然sin^4a/1 是怎么回事？
2> 1-cos^6 后面是不是少了个a？ 1-cos^6a
cos^4a 是cos的4次方么？

化简1-sin^4a-cos^4a/1-sin^6a-cos^6a 1-sin^6a-cos^6a分之1-sin^4a-cos^4a 化简化简 1-sin^4a-cos^4a/cos^2a-cos^4a 化简(1-sin^6 a-cos^6 a)/(cos^2 a-cos^4 a)== 化简：(sin^6a+cos^6a-1) / (sin^4ª+cos^4a-1) (1-sin^4a-cos^4)/(sin^2a-sin^4a) 化简化简1-cos^4a-sin^4a/1-cos^6-sin^6acos^6应为cos^6a 化简tan a(cos a-sin a)+sin a(sin a+tan a)/1+cos a （1-sin^6a-cos^6a)/(1-sin^4a-cos^4a)=? (1-sin^4a-cos^4a)/(1-sin^6a-cos^6a) 化简[1-cos^4(A)-sin^4(A)]/[1-cos^6(A)-sin^6(A)] 等于多少? 化简[1-cos^4(A)-sin^4(A)]/[1-cos^6(A)-sin^6(A)] 等于多少? 化简[1-cos^4(A)-sin^4(A)]/[1-cos^6(A)-sin^6(A)] 等于多少?急用! 化简[1-cos^4(A)-sin^4(A)]/[1-cos^6(A)-sin^6(A)] 等于多少?急用! 化简[1-cos^4(A)-sin^4(A)]/[1-cos^6(A)-sin^6(A)] 等于多少?急用! 8sin(45+a)sin(45-a)=1,sin^4a-cos^4a= (1-sin^6a-cos^6a)/(sin^2a-sin^4a) cosA+cos^2A=1,sin^2A+sin^4A+sin^8A