I'm wrapping up my research project.
n⁴+4
=(n²+2i)(n²-2i)
=(n+1+i)(n-1-i)(n+1-i)(n-1+i)
=(n+1+i)(n+1-i)(n-1-i)(n-1+i)
=((n+1)²+1)((n-1)²+1),
where the last equality is by a difference of squares.
Note that each factor is greater than 1 when n>1. Q.E.D.
n⁴+4
=(n²+2i)(n²-2i)
=(n+1+i)(n-1-i)(n+1-i)(n-1+i)
=(n+1+i)(n+1-i)(n-1-i)(n-1+i)
=((n+1)²+1)((n-1)²+1),
where the last equality is by a difference of squares.
Note that each factor is greater than 1 when n>1. Q.E.D.
Use the difference of two squares to get the square root of (243×3), which is 27 (by breaking 243 into into prime decomposition; it is a power of 3).
Easy.
Use the difference of two squares to get the square root of (243×3), which is 27 (by breaking 243 into into prime decomposition; it is a power of 3).
Easy.