# Math Help - Finding the domain....urgent help needed

1. ## Finding the domain....urgent help needed

How do I find the domain? Could someone please assist me through one of these problems? I vaguely remember going over this but I need to review this material...any assistance would be great!

2. $f(x)=\sqrt{x+2}.$

$x+2\ge0,$ 'cause you cannot have a negative quantity.

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For the second one, observe that $x^2+3x-10=(x-2)(x+5).$ What should it be the expected domain?

3. would it be X + 5? because you cannot have a negative?

4. Not exactly.

On the denominator, the values $2,-5$ make this one zero, then you'll get something like $\frac a0$ and that deserves a punishment.

So the domain will be $\text{Dom}\,f=\mathbb R-\{2,-5\}.$