F(x) = [[x]], what is f(0.9)? f(0.9) = -1 f(0.9) = 0 f(0.9) = 0.9 f(0.9) = 1 f(0.9) = -0.9

I believe the answer you're looking for is f(0.9) = 0.9

If you replace the first x with 0.9, you will be replacing any other x's in the problem with that value as well.

Since f(x) = x

f(0.9) = 0.9

(n^3 - n)

= n(n-1)(n+1)

since it is divisible by 3 and 2 ,because it is a multiple 3 consecutive number

if, n-1 is odd then n+1 is also odd, then it is a multiple of 9

but if, n-1 is even then n+1 is also even, then it is a multiple of 4

so, largest multiple = max(9*2, 4*3) = max(18, 12) = 18