Question

find all zeroes of f(x)= x^3 - 6x - 9

Answer 1

if it is a rational number you only have a few choices, namely
\[\pm1,\pm3,\pm9\]

Answer 2

1 and minus one you can do in your head, and they don't work. try 3

Answer 3

once you check that \(f(3)=0\) you can factor as \((x-3)(\text{something})\) and then the other two zeros you can find using the quadratic formula. they are complex