Помогите с английским. Срочно нужно!

Здравствуйте,прошу помочь,пожалуйста очень срочно, надо определить функцию инфинитива в этих предложениях:
1. The teacher told her students to learn the poem by heart.
2. To translate a sentence is to discover its meaning.
3. His task was to complete the work in time.
4. The material to be employed has been carefully tested.
5. He was the first to make the experiment.

извините не тот вариант, это рашать не нужно