Question

How do I use a graphing calculator to find the complex zeros of `f(x)=x^3-4x^2+25x-100`?

Answer 1

I'll try doing it without the GC:

You may have noticed that the function can be rewritten:

`f(x)=x^2(x-4)+25(x-4)->`
`f(x)=(x^2+25)(x-4)->`

If `f(x)=0` then the only real root is `x=4`

And the complex roots come from
`x^2=-25->x=5i or x=-5i`

Btw I have no idea how to do this with a GC.