A reflection of the function [tex]y=f(x)[/tex] in the x-axis forms from the function [tex]y=f(x)[/tex] th function [tex]y=-f(x).[/tex]
When reflecting the function [tex]f(x)=x^2+3[/tex] in the x-axis, you will get the function
[tex]g(x)=-f(x)=-(x^2+3).[/tex]
Eliminate brackets, then
[tex]g(x)=-x^2-3.[/tex]
Answer: correct choice is A
