Question

写出下列特称命题或全程命题的否定,判断真假并说明理由

Answer 1

1,Ex,y∈R,有：.(x+y)^2=0,可推出:∨x,y∈R.(x+y)^2≥4xy

2.:∨x,∈R,sinx+cosx≠√3,.真命题：√3=sinx+cosx=√2sin(x+45*)

sin(x+45*)=√1.5>1