# Name for two function the sum of which is a PDF

A continuous random variable $$X$$ is defined in a domain $$A$$ which is the union of two non-overlaping subdomains $$B$$ and $$C$$. When analysing the distribution of $$X$$, one could calculate the PDF of $$X$$ considering the whole domain $$A$$, or two PDFs, one for each subdomain separately.

It proved more useful to calculate two functions, one for each subdomain, normalized in such a way that the integral of each function equals the relative size of the subdomain to the whole domain. The sum of these two functions is a PDF, but not each one individually. Is there a name for such a function?

• Would "partial probability distribution function" work? – toliveira Mar 14 at 22:20
• It's a mixture distribution. – dnqxt Mar 15 at 0:50
• I understand that the sum of those two functions is a mixture distribution. Is there a name to refer to each of the functions? – toliveira Mar 25 at 19:24
• Mixand or mixture component – dnqxt Mar 25 at 19:37
• Thank you, dnqxt! I would like to accept it as the answer to register it for future users. If you don't mind, could you please copy it into the answer? – toliveira Mar 27 at 11:54

## 1 Answer

Such functions may be called mixands or mixture components.