To find the equation of the dotted graph, which is a reflection of the solid graph (a cubic function), we first need to understand how reflections work.
The equation of the solid graph is given as: \[ f(x) = x^3 + 1. \]
When we reflect a graph across the x-axis, the transformation applies to the output of the function. This means we replace \( f(x) \) with \( -f(x) \).
So, reflecting \( f(x) \): \[ g(x) = -f(x) = - (x^3 + 1) = -x^3 - 1. \]
Now, among the options provided, we look for a match with our derived equation \( g(x) = -x^3 - 1 \).
- Option #1: \( g(x) = -x^2 + 1 \) (not a match)
- Option #2: \( g(x) = -x^3 - 1 \) (this is a match)
- Option #3: \( g(x) = -x^3 + 1 \) (not a match)
- Option #4: \( g(x) = x^3 - 1 \) (not a match)
Therefore, the correct option is Option #2: \( g(x) = -x^3 - 1 \).