determine受動態能動態

please refer to the weblio dictionary.
refer to the definition of the word 'determine'.
refer to the definition of the verb 1-a.(transitive verb)
I determined to solve the mystery.

refer to the definition of the word 'determined'.
refer to the definition of the adjective 2.(adjective).
I was determined to solve the mystery.
I suppose this sentence is not a form of passive voice.
because this determination decided by oneself .

:determine.
https://ejje.weblio.jp/content/determine
:determined.
https://ejje.weblio.jp/content/determined