Question

What are the possible rational zeros of f(x) = x4 + 2x3 – 3x2 – 4x + 20

Answer 1

Use the rational zero theorem to test for zeros.

\[a _{n}=1\]\[a _{0}=20\]\[a _{0}/a _{n}\]So the possible rational zeros will be at \[\pm1, \pm2,\pm4,\pm5,\pm10,\pm20\]

So plug them into your equation to see if you get 0=0