Question

what is the domain of f(x)=sqrt(x+4) over x

Answer 1

Anything below a square root sign has to be positive or zero. >= means greater than or equal to. So x+4>=0. That means x>=-4 BUT x cannot equal zero because x is in the denominator. It's not ever possible to divide by zero. So the domain is x>=-4 AND x not equal to 0.