题目内容
答案:
化简cos(π+)sin(π+)+tan(-β)cos(-β)+tan(π-)·cos2(2π-)等于
( )
A.sin
B. -sinβ
C.sinβ
D. cos
如果x满足<0,那么化简的结果是
A.2x-1
B.1-2x
C.3-4x
D.4x-3
化简(sin6α+cos6α)+3sin2αcos2α的结果是 ( )
A.-1 B.1 C.0 D.2
A.sin(2a + b ) B.cos(a -2b )
C.cosa D.cosb