If f (x) = StartRoot 4 x + 9 EndRoot + 2, which inequality can be used to find the domain of f(x)?
StartRoot 4 x EndRoot greater-than-or-equal-to 0
4 x + 9 greater-than-or-equal-to 0
4 x greater-than-or-equal-to 0
StartRoot 4 x + 9 EndRoot + 2 greater-than-or-equal-to 0