求值:arccos(cos4/5π)=

求值:arccos(cos4/5π)= 求值arcsin(sin2)+arccos(cos4) arccos(cos4)求值 sin(2arcsin1/3)求值 cos[arccos3/5+arccos(-12/13)]求值 求值cosπ/5cos2π/5cos4π/5cos8π/5 cosπ/5=cos4π/5, cos4π=? 反三角函数求值arccos(cos5π/4)=?arctan(tan4π/3)=?arcsin(sin6)=? 有关反三角函数的计算（急求）1.arcsin(cos4)=?2.arccos(sin4)=?4-3π/2 2.4-π/2如何计算, 求值：cos2π/7 * cos4π/7 * cos6π/7 求值cos2π/9*cos4π/9*8π/9 求值:cos2π/7cos4π/7cos8π/7 求值cos2π/9cos4π/9cos8π/9 tan(arcsin(1/3)+arccos(-1/5))求值 求值sin[arccos(-3/5)+pai/6]如题, 已知sin4次方-cos4次方=5/9,求cos4 求值：arccos(-√3/2) arccos(cosπ/4)=cos(arccosπ/4)对吗?