04 × 10 quartic power, accurate to the thousandth position______ , yes______ A significant number. Brother and sister help, I don't understand

04 × 10 quartic power, accurate to the thousandth position______ , yes______ A significant number. Brother and sister help, I don't understand

The fourth power of 3.04 × 10 is about 3.0 × 10 ^ 4, which has two significant numbers

If a B ∈ n, f (a + b) = f (a) * f (b), then f (2) / F (1) + F (3) / F (2) +. F (2005) / F (2004)

f(2)／f(1)+f（3）／f（2）+.f（2005）／f（2004）=f(1+1)／f(1)+f（2+1）／f（2）+.f（2004+1）／f（2004）= f(1)*f(1)／f(1)+f（2）*f(1)／f（2）+.f（2004）*f(1)／f（2004）=f(1)+f(1)+.+f(1)=2004*f(1)...

Let f (n) = 1 + 2 + 3 +.. + 3N, then f (2005) - f (2004) =?

f(n)=1+2+3+..+3n
f(2005)-f(2004)
=[1+2+3+..+3(2005) ]- [1+2+3+..+3(2004) ]
=6013+6014+6015
=18042