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

No.

While the spelling and core meaning of "tenta" are identical in both dialects, there is a difference in typical usage and grammatical person. In Brazil, "tenta" is most commonly used as the 3rd person singular (referring to ele, ela, or the standard você). When a Brazilian wants to give a command to você, they typically use the form "tente." In Portugal, "tenta" is the standard imperative (command) for the 2nd person singular (tu), which is the most natural way to address friends and family.

Brazilian Portuguese Examples

1. O cachorro tenta pular o muro. (The dog tries to jump the wall.)
2. A gente tenta chegar cedo. (We try to arrive early.)
3. A menina tenta o bolo. (The girl tries the cake.)
4. Ele tenta pegar a bola. (He tries to catch the ball.)
5. Tenta não ficar bravo, tá? (Try not to get angry, okay?)

Continental Portuguese Examples

1. O cão tenta saltar o muro. (The dog tries to jump the wall.)
2. Nós tentamos chegar cedo. (We try to arrive early.)
3. A miúda tenta o bolo. (The girl tries the cake.)
4. Ele tenta apanhar a bola. (He tries to catch the ball.)
5. Tenta não ficar zangado. (Try not to get angry.)