what can a denominator never be?
0
so, we need to figure what x can't be... the only way to multiply 2 things together to get 0 is if one or both are zero.
so, what x values make our denominator 0?
to figure this out, we need to set (x-1)(x-2)=0
now we split and solve.
[tex]x - 1 = 0 \\ x - 2 = 0[/tex]
so when x is 1 or 2 the function doesnt make sense.
but, x can be every other number and it does, so the answer is
ALL REAL NUMBERS not equal to 1 or 2
