f(a)=sin(a+π/2)cos(3π/2-a)tan(2π-a)÷{tan(-a-3π）sin(-a-2π)}=cosa(-sina)(-tana)÷{[-tan(a+3π)][-sin(a+2π)]}=cosasinatana÷{[-tan(a+π)][-sina]}=cosasinatana÷{tan(a+π)sina}=cosasinatana÷{tana...