When considered as a whole, both of your phrases are fragments. They lack a subject and a verb.
First sentence suggestion:
It (subject)
shows (verb)
<-- direct object start -->
a powerful graphical representation of your company's price, providing MAX, MIN and LIST prices.
<-- direct object end -->
Second sentence suggestion:
This paragraph (subject)
teaches (verb)
<-- direct object start -->
how to read our graphics correctly.
<-- direct object end -->
You
may write sentence fragments when designing a webpage. The audience expects concise language.
Sentence fragments are particularly suited to advertising/explaining/highlighting features.
The key to a good webpage is how the fragments are used or laid out.
Examples:
How to Read Our Graphics Correctly
The title tells the audience what information this paragraph contains. In English, we capitalize the important words in a title and it looks good if it appears in boldface type.
Our product provides
- A powerful graphical representation ...
- Another feature goes here
Each item in the list above begins with 'Our product provides', so the subject/verb requirement is satisfied. That way you have no fragments.