1.Let P(x,y) be the statement “x + y = x - y”, what are true value of "y "x P(x,y) and "x "y P(x,y), where the domain consists of all real numbers?
2.Let P(x,y) be the statement “x2 + y2 = 5”, what are true value of $y $x P(x,y) and $x $y P(x,y), where the domain consists of all real numbers?
3.Find the argument form for the follow argument and determine wheter it is valid. Can we conclude that the conclusion is true if thepremises are true?
If george does not have eight legs, then he is not an insect.
George is an insect./George has eight legs.
4.Let P(x,y) be the statement “xy = y”, what are true value of $y "x P(x,y) and "x $y P(x,y), where the domain consists of all real numbers?
5.Show pÙ(qÚr) « (pÙq) Ú (pÙr) is a tautology.
這五題是我不會做的題目,明天就要交了,可是可是可是............我還寫不出個所以然
有沒有人會?拜託教教我................
題目轉阿轉的,頭都暈了.....
小妹我在此感激不盡~~~~~