Let S=the solution set for x² = 16.
and T=the solution set for x+2 = 16.
List the elements of each set.
a.S Ç T b. S È T
x² = 16
x² - 16 = 0
(x - 4)(x + 4) = 0
Set each factor = 0:
Setting x - 4 = 0 gives solution x = 4
Setting x + 4 = 0 gives solution x = -4
So S = {4, -4}
x + 2 = 16
x = 14
So T = {14}
S È T = {4, -4} È {14}
The union of two sets is the set of every element
that is either an element of S, an element of T,
or an element of both sets.
So S È T = {4, -4, 14}
The intersection of two sets is the set of every
element that is an element of both sets:
S Ç T = {4, -4} Ç {14} = {} or Æ,
that is, the empty or null set, since there are
no elements that both S and T have in common.
Edwin