Thank you for the opportunity to help you with your question!
Basically the first sentence is talking about the y values, the second sentence is talking about the x values.
When it says "all local minimum values of h" it's talking about all of the "y" values, in other words where the minimum point is.
Second sentence, "ALL VALUES at which h has a local minimum" means it wants to know all of the "x" values WHERE the minimum points are located. Please let me know if you need any clarification. I'm always happy to answer your questions.