Directly related to "determine":
* Determined: (adjective) resolved, resolute, firm in purpose
* Determination: (noun) firmness of purpose, resolve
* Determinable: (adjective) capable of being determined
* Indeterminable: (adjective) impossible to determine
* Predetermined: (adjective) decided beforehand
* Self-determined: (adjective) having control over one's own destiny
* Overdetermined: (adjective) excessively determined or influenced
Less direct, but related to the concept of "determination":
* Determinism: (noun) the doctrine that all events are predetermined and unavoidable
* Deterministic: (adjective) relating to determinism
* Indeterminism: (noun) the doctrine that events are not predetermined
* Determinant: (noun) a factor that decisively affects the outcome of something
Let me know if you would like more examples or want to explore the root word "determine" in more depth!