1、f(x)=cos(x/2)+cos(π/2-x/2)=cos(x/2)+sin(x/2)=√2[sin(x/2)*√2/2+cos(x/2)*√2/2]=√2[sin(x/2)cosπ/4+cos(x/2)sinπ/4]=√2sin[(x/2)+π/4]所以T=2π/(1/2)=4π2、f(a)=cos(a/2)+sin(a/2)=2√10/5平方cos&s...