ok, so a factor of n!+3 is 3, and a factor of n!+2 is 2 and so on.
So a factor of n!+n is n. This shows that none of them is prime.
How would i go about doing the second part of the question?
Is (n factorial + 2) a factor of it?
Which would then apply to the others, which would show that none of them were prime.
For them each to be prime, their only factors would have to be themselves and 1.
Homework Statement
Let n be a part of the natural numbers, with n>=2. Consider the numbers [n factorial +2 ], [n factorial + 3], ..., [n factorial + n].
Prove that none of them is prime, and deduce that there are arbitrarily long finite stretches of consecutive non-prime nummbers in the...
Homework Statement
From fermat's little theorem deduce that when p is prime,
n^p is equivalent to n (mod p)
for all integers n.
Homework Equations
The Attempt at a Solution
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Homework Statement
Find the limit of f(x)=[xcosx]/[x^3 + 1] as x tends to infinity.
Homework Equations
The Attempt at a Solution
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Without using l'hop i know...
Homework Statement
Show that the following series converges:
Homework Equations
Sum of (from n=1 to infinity) of [3^n + 4^n] / [3^n + 5^n]
The Attempt at a Solution
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Homework Statement
Evaluate the following intergral:
Homework Equations
Intergral from gamma of (y)dz, where gamma is the union of the line segments joining 0 to i and then i to i+2
The Attempt at a Solution
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Homework Statement
For the following set, state and justify whether or not it is open or closed.
Homework Equations
A={z| I am z >1}
The Attempt at a Solution
I know the definition of an open set, but I am not sure how to use it to solve this question.