函数y=sin(派除以4-x)的导数为(       )A.
y=sin(派除以4-x)的导数为(       ) A.-cos(派除以4+x) B.cos(派除以4-x) C.-sin(派除以4-x) D.-sin(x+派除以4)
选D 函数y=sin(π/4-x)的导数为: y'=-cos(π/4-x)=-sin[π/2-(π/4-x)]=-sin(π/4+x)