has been conjectured that there are infinitely many twin primes.\ 2.8. Let

P(n):(n^(2)+5n+6)/(2)

is even.\ (a) Find a set

S_(1)

of three integers such that

P(n)

is an open sentence over the domain

S_(1)

and

P(n)

is true for each

ninS_(1)

.\ (b) Find a set

S_(2)

of three integers such that

P(n)

is an open sentence over the domain

S_(2)

and

P(n)

is false for each

ninS_(2)

.

has been conjectured that there are infinitely many twin primes. 2.8. Let P(n):2n2+5n+6 is even. (a) Find a set S1 of three integers such that P(n) is an open sentence over the domain S1 and P(n) is true for each nS1. (b) Find a set S2 of three integers such that P(n) is an open sentence over the domain S2 and P(n) is false for each nS2