So, generally speaking, the name of a fatty acid is derived from the hydrocarbon component. So we begin with the hydrocarbon name, remove the E at the end of the name and simply replace it with OIC and then add acid. The acid is there because we also have that carboxylic acid at the end of that hydrocarbon name. Now, in this particular case, things were pretty simple because we didn't have any double bonds. Now what happens if we have one double bond? How can we incorporate the double bond into this name?