Question

How do you find all zeros of the function `f(x) = x^2 - 12x + 20`?

Answer 1

zeros of `f(x)` are `x=2` and `x=10`

Explanation:

`f(x)=x^2-12x+20`

We look for two numbers which when multiplied together equal `20`
and which when added together equal `(-12)`

With a bit of though we come up with `(-2)` and `(-10)`
which allows us to factor:
`f(x)=x^2-12x+20=(x-2)(x-10)`

For `f(x)` to be zero
either
`color(white)("XXX")(x-2)=0 rarr x=2`
or
`color(white)("XXX")(x-10)=0 rarr x=10`