由已知可得,T/2=7π/8-3π/8=π/2,所以T=π=2π/w,则w=2.当f(3π/8)=2sin(3π/4+φ)=2,必有f(7π/8)=2sin(7π/4+φ)=-2sin(3π/4+φ)=-2,二式完全等价 因此,只能确实,f(3π/8)=2sin(3π/4+φ)是极值点,但不能确实是...