adjective from business

Solution 1:

There's no specific adjective form of business. Instead, business is generally used as a noun adjunct (or attributive noun):

the business applications of mathematics

Solution 2:

The adjective that typically goes with business is commercial:

the commercial applications

However, there’s really no need of that, since business makes a perfectly fine noun adjunct:

A noun adjunct, also called an attributive noun, is when one noun is used to give an attribute to another noun, like dog catcher, dog food, house sitter, heart surgery, running shoes, employee compensation, and Peter Principle. It is an alternative to a prepositional phrase, like food for dogs or surgery of the heart. A predicate test can be used to distinguish a noun adjunct from an adjective.

In other words, in a business application, the word business is a noun not an adjective because it fails the predicate test:

*The application is business. [WRONG: therefore not an adjective]

Whereas with commercial passes it:

The application is commercial. [RIGHT: therefore yes an adjective]

However, business doesn’t need to be an adjective, nor does it need to be turned into one. It’s perfectly fine to use nouns to modify other nouns in noun–noun compounds like this.

Treat it as a compound noun with a space in it if you prefer. Babysitter and baby food are both the same sort of word, and the space in the latter is an orthographic red herring that tricks people who are too bent on misapplying old-fashioned Latin POS assignments to English.