If P (n) is the statement “n2 – n + 41 is prime”, prove that P (1), P (2) and P (3) are true. Prove also that P (41) is not true.
If P (n) is the statement “n2 – n + 41 is prime”, prove that P (1), P (2) and P (3) are true. Prove also that P (41) is not true.

According to ques:

    \[P\left( n \right)\text{ }=\text{ }{{n}^{2}}~\text{ }n\text{ }+\text{ }41\]

is prime.

 

    \[P\left( n \right)\text{ }=\text{ }{{n}^{2}}~\text{ }n\text{ }+\text{ }41\]

Or,

    \[P\text{ }\left( 1 \right)\text{ }=\text{ }1\text{ }\text{ }1\text{ }+\text{ }41\]

    \[=\text{ }41\]

P (1) is Prime.

Similarly,

    \[P\left( 2 \right)\text{ }=\text{ }{{2}^{2}}~\text{ }2\text{ }+\text{ }41\]

    \[=\text{ }4\text{ }\text{ }2\text{ }+\text{ }41\]

    \[=\text{ }43\]

P (2) is prime.

Similarly,

    \[P\text{ }\left( 3 \right)\text{ }=\text{ }{{3}^{2}}~\text{ }3\text{ }+\text{ }41\]

    \[=\text{ }9\text{ }\text{ }3\text{ }+\text{ }41\]

    \[=\text{ }47\]

P (3) is prime

Now,

    \[P\text{ }\left( 41 \right)\text{ }=\text{ }{{\left( 41 \right)}^{2}}~\text{ }41\text{ }+\text{ }41\]

    \[=\text{ }1681\]

P (41) is not prime

Hence, P (1), P(2), P (3) are true but P (41) is not true.