so x+2 is under the square root sign so
[tex] \sqrt{x+2} [/tex]-2x
domain is all possible numbers that will give a real solution (no square root of negative)
so solve for numbers that make the radicand negative
x+2
x+2<0
subtract 2
x<-2
so therefor x has to be less than -2 to make the radican negative
remember that square root of 0=0 so we can have 0 as inside
so domain is all real numbers greater than or equal -2 or
[-2, ∞) aka x>-2
