求值sin^4(π/8)+cos^4(π/8) 答对有分`

求值:sin(26π/3)+cos(-17π/4)= sin(-π/4)求值 求值sin^4(π/8)+cos^4(π/8) 答对有分`求值sin^4(π/8)+cos^4(π/8)```过程 sin^4 (5π/8）-cos^4 （5π/8） 求值 求值sin^4(π/8)+cos^4(π/8) 答对有分` sin(π+π/6)-cos(π+π/4)cos(-π/2)+1求值 cos^6(π/8)-sin^6(π/8)=求值,[cos^2(π/8)-sin^2(π/8)][cos^4(π/8)+sin^4(π/8)+cos^2(π/8)sin^2(π/8)]=cos(π/4)[1-cos^2(π/8)sin^2(π/8)]=cos(π/4)[1-[sin^2(π/4)]/4]==7√2/16 sin²(π/8)-cos²(π/8)求值 求值sinπ/8乘cosπ/8过程 求值sinπ/8乘cosπ/8过程 求值：sin(π/12)+cos(π/12) sin(-4分之π)求值 sin 11π/4 求值 sin^4pai/8+cos^4pai/8求值 8sin(π/32)cos(π/32)cos(π/16)cos(π/8),求值 求值：sin(π/4)cos(19π/6)tan(21π/4)急! 求值:sin(-31π/6)-cos(-10π/3)-sin11π/4 已知sinα+cosα=1/5,求值：（1）sinαcosα；（2）sin³α+cos³α；（3）sin四次方α+cos四次方αsinα+cosα=-1/5,且α∈（0,π）,则tanα=_________sinα+cosα=-1/8,且α∈（π,5/4π）,则sinα-cosα=___________已知sec