To find the zeros of `f(x) = x^2 - 2x - 8` set f(x) = 0.

`x^2 - 2x - 8 = 0` Factor the expression.

`(x - 4) (x + 2) = 0` Set each factor equal to zero and solve for x.

`x - 4 = 0` and `x + 2 = 0`

`x = 4and x = -2`

**The zeros of the function are 4 and -2.**

Find the domain of `f(x) =sqrt(x) - 7`

The domain of a function is all the possible inputs for a function, or all the possible values that x can take on.

"x" can not be negative as this would give a non-real solution. Therefore, x must be greater than or equal to zero.

**The domain is: `{x|x inRR, x>= 0}` **

**or `[0,oo)` **

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