P(1) means we are just adding all of the coefficients, of which there are n+1 by nature of being degree n. Hence, the minimum greatest coefficient is 2n^2/n+1=2n - 2/n+1 and because n>=2, n+1>=3 and therefore 2/n+1 is less than 1, so by PHP, there must be at least one coefficient of P(x) which is at least 2n-1
