Math Is Fun Forum

Thanks Jane, but if say lx-1l<0, why must it be equal to -x+1???
Also how do you determine the considered regions, I can understand graphically but not algebraically.

All primes are odd apart from 2, so p+1 either equals 2+1=3 or an (odd number +1)=even number "n^3".
As 3 is not a cubed integer we know that p≠2.  This means "n^3" is even, thus meaning "n" must be even as (even)^3=even and (odd)^3=odd, and as 2 is the only even prime number, n=2
therefore, p+1=2^3=8
Meaning p=7

what do you mean by "i"???...imaginary number? :S

I understand everything apart from the first line...how do you know that f'(x)=1/(xlna) if f(x)=loga(x) ???
also the answers tell me that the answer is 1+(1/x) :S

thanks though luca, I hate to be a bother

well i'm presuming log with base 10 but i dont actually know for sure, i just copied the questions exactly :S