Determine the truth value of the following statements if theuniverse of discourse of each variable is the set of realnumbers.
1. ?x(x2=?1)?x(x2=?1)
2. ?x?y?0(xy=1)?x?y?0(xy=1)
3. ?x?y(x2=y)?x?y(x2=y)
4. ?x?y(x+y?y+x)?x?y(x+y?y+x)
5. ?x?y(xy=0)?x?y(xy=0)
6. ?x?y(x=y2)?x?y(x=y2)
7. ?x?y?z(z=x+y2)?x?y?z(z=x+y2)
8. ?x?0?y(xy=1)?x?0?y(xy=1)
9. ?x(x2=2)?x(x2=2)
10. ?x?y(x+y=1)?x?y(x+y=1)
11.?x?y((x+2y=2)?(2x+4y=5))?x?y((x+2y=2)?(2x+4y=5))
12. ?x?y((x+y=2)?(2x?y=1))
