I don't understand this, can you help with the following.... when G(x)=0 then the domain is different. G=0 wouldn't be a real number. example would be f=(G)=x+2 f(F)=2x+3 x=2

To understand the given problem, let's break it down step by step.

1. You mentioned that G(x) = 0. This means that when we substitute the value of x such that G(x) equals zero, it represents a specific point on the graph of the function G(x). In this particular case, the equation G(x) = 0 represents a horizontal line on the graph.

2. Next, you mentioned that the domain is different when G(x) equals zero. The domain of a function refers to the set of all possible input values, which in this case is x. When G(x) = 0, it means that x can take on any value since any value of x would result in G(x) being zero.

3. However, you correctly pointed out that G = 0 would not be a real number. It seems like there may be some confusion here. It is important to distinguish between the function G(x) and the value that the function evaluates to at a specific x-value.

4. In your example, you mentioned a second function f(x) = 2x + 3. When you write f(F) = 2x + 3, it appears that "F" is a placeholder for the input value. If we substitute x = 2 into f(x), we get f(2) = 2(2) + 3 = 7.

To summarize, the equation G(x) = 0 represents a horizontal line on the graph, where any value of x would result in G(x) being zero. In the example you provided, substituting x = 2 into f(x) = 2x + 3 gives us f(2) = 7.