Nomenclature of alkenoic acids - which group has priority: the alkene or the acid? Right, how do you systematically name them? Also, do you number them from the double bond end or the Carboxyl end?

Ie would it be something like.  2-methyl Hept-3-enoic acid?

Scuse the bad question and I made up the example, sorry! I'm really confused!

Thanks!!
The carboxylic acid moiety takes precedence over the alkene moiety, so the molecule has to be numbered starting from the carboxylic acid carbon. Hence, methacrylic acid, for example, has the systematic IUPAC name of 2-methylpropenoic acid.