Question

For a polynomial $$f(x)$$, $$f(-1)$$ and $$f(2)$$ are both equal to zero. Which of the following is a factor of $$f(x)$$?

Options

• $$x^2 + x - 2$$

• $$x^2 - x - 2$$

• $$x^2 + x + 2$$

• $$x^2 - 2x + 1$$

Answer 1

x² – x – 2

Explanation:

The zeros $$-1$$ and $$2$$ give factors $$(x + 1)$$ and $$(x - 2)$$, whose product is $$x^2 - x - 2$$.