Intercepts Cubic
1. **State the problem:** Find the x- and y-intercepts of the function $$f(x)=x^3-2x^2-24x$$.
2. **Find y-intercept:** The y-intercept occurs when $$x=0$$. Evaluate:
$$f(0)=0^3 - 2(0)^2 - 24(0) = 0$$
So, the y-intercept is at $$(0, 0)$$.
3. **Find x-intercepts:** The x-intercepts occur when $$f(x) = 0$$:
$$x^3 - 2x^2 - 24x = 0$$
Factor out $$x$$:
$$x(x^2 - 2x - 24) = 0$$
Set each factor to zero:
- $$x = 0$$
- $$x^2 - 2x - 24 = 0$$
4. **Solve quadratic equation:**
Use the quadratic formula $$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$ for $$x^2 - 2x - 24 = 0$$ where $$a=1$$, $$b=-2$$, $$c=-24$$:
$$x = \frac{-(-2) \pm \sqrt{(-2)^2 - 4(1)(-24)}}{2(1)} = \frac{2 \pm \sqrt{4 + 96}}{2} = \frac{2 \pm \sqrt{100}}{2}$$
5. **Calculate roots:**
$$\sqrt{100} = 10$$
So the roots are:
$$x = \frac{2 + 10}{2} = 6$$ and $$x = \frac{2 - 10}{2} = -4$$
6. **List x-intercepts:** The x-intercepts are at $$(0, 0)$$, $$(6, 0)$$, and $$(-4, 0)$$.
**Final answer:**
- Y-intercept: $$(0, 0)$$
- X-intercepts: $$(0, 0), (6, 0), (-4, 0)$$