求值：log2cos(pai/9)+log2cos(2pai/9)+log2cos(4pai/9)pai代表圆周率

求值：log2cos(pai/9)+log2cos(2pai/9)+log2cos(4pai/9)pai代表圆周率 求值：log2cosπ/9+log 求值：log2cosπ/9+log2cos2π/9+log2cos4π/9 求值：log2cos派/9+log2cos2派/9+log2cos4派/9 求值：log2cosπ/9+log2cos2π/9+log2cos4π/9. 求y=log2cos(3分之x+4分之pai)单调增区间 求值 tan(-23pai/6) 求值log2sin(π/8)+log2cos(π/8)2是以2为底 求值Cos pai/17 *cos 2pai/17*cos 4pai/17*cos 8pai/17 求值:cos(2pai/7)+cos(4pai/7)+cos(6pai/7)pai打不出,不好意思 sin^4pai/8+cos^4pai/8求值 cos(-pai-a) 化简求值 cos(pai/15)×cos(2pai/15)×cos(3pai/15)×cos(4pai/15)×cos(5pai/15)×cos(6pai/15)×cos(7pai/15)求值 cos(pai/15)×cos(2pai/15)×cos(3pai/15)×cos(4pai/15)×cos(5pai/15)×cos(6pai/15)×cos(7pai/15)求值 sin (pai/14)sin(3pai/14)sin(5pai/14)求值 Lo 求值cos(2arctan根号6+pai/3) 求值sin[arccos(-3/5)+pai/6]如题,