I'm trying to find the domain for the function: square root of (9-x^2)...So what I do is solve for 9-x^2 >= 0 (b/c you can't have a negative number under a radical)...and get x is less than or equal to +3 and -3....

but the domain is supposedly [-3,3]...which would mean x > or = -3....but when I solved for it I got that x < or = -3...IT DOESN'T MAKE SENSE...

someone please explain