Is the word tentar the same in Brazilian and European Portuguese?

No

While the fundamental meaning and spelling of "tentar" are identical in both dialects, the answer is No because there are significant differences in grammatical usage and syntax. In Brazil, it is standard to place object pronouns before the verb (e.g., "me ajudar"), whereas in Portugal, they are placed after the verb (e.g., "ajudar-me"). Additionally, the way the verb is conjugated to address others differs, as Brazil predominantly uses the você form, while Portugal frequently uses the tu form.

Brazilian Portuguese Examples

1. "Ele tentou me ajudar com a mudança." (He tried to help me with the move.)
2. "Você tentou ligar para ela ontem?" (Did you try to call her yesterday?)
3. "Eu vou tentar terminar esse relatório hoje." (I'm going to try to finish this report today.)
4. "A gente vai tentar chegar um pouco mais cedo." (We are going to try to arrive a bit earlier.)
5. "Não tente fazer isso sozinho, é perigoso." (Don't try to do this alone, it's dangerous.)

Portuguese (Portugal) Examples

1. "Ele tentou ajudar-me com a mudança." (He tried to help me with the move.)
2. "Tu tentaste ligar-lhe ontem?" (Did you try to call her yesterday?)
3. "Eu vou tentar acabar este relatório hoje." (I'm going to try to finish this report today.)
4. "Nós vamos tentar chegar um pouco mais cedo." (We are going to try to arrive a bit earlier.)
5. "Não tentes fazer isso sozinho, é perigoso." (Don't try to do this alone, it's dangerous.)