求下列函数的导数(1)y=sin∧4(x/4)+cos∧4 (x/4)（2）y=㏑x/x
问题描述：
求下列函数的导数(1)y=sin∧4(x/4)+cos∧4 (x/4)（2）y=㏑x/x
答
1)y=Y=4sin3(x/4)*cos(x/4)*1/4+4cos3(x/4)*(-sin(x/4))*1/4
=sin(x/4)cos(x/4)(sin2(x/4)+cos2(x/4))
=sin(x/4)cos(x/4)
2)Y=(x*1/x-1*lnX)/x2
=(1-lnX)/X2