化简：1+tan(丌+a)/1+tan(2丌-a)=3+2√2
1+tan(a)/1-tan(a)=3+2√2
tan(a)= √2/2
sina = √2/2cosa
(sina)^2+(cosa)^2 = 1
所以,sina = ±1/√3
cosa = ±√2/√3
化简：cos2（丌-a）+sin（3丌/2+a)+cos(丌/2+a)+2sin2(a-丌)
=cos2a - cosa -sina + 2sin2a
= (cosa)^2 - (sina)^2-cosa-sina+2sina.cosa
=（2√2+1±（√3+√6））/3