.
(1) a =
, b =
. a and b are irrational, but a+b = 1 is rational.
a =
, b =
. a and b are irrational, and a+b =
is irrational.
(2) a =
, b =
. a and b are irrational, but a-b = 1 is rational.
a =
, b =
. a and b are irrational, and a-b =
is irrational.
(3) a =
, b =
. a and b are irrational, but a*b = 2 is rational.
a =
, b =
. a and b are irrational, and a*b =
is irrational.
(4) a =
, b =
. a and b are irrational, but a/b = 1 is rational.
a =
, b =
. a and b are irrational, and a/b =
is irrational.
Solved.