4. Write a function that takes in a number n >0 and prints the sum of the numbers 0 to n. input: int output: int 5. Write a function that concatenates two lists and removes duplicates. input: list, list output: list 6. Write a function that takes in the radius of a circle compute the area of the circle. input: float output: float 7. Write a function that creates a file with a specific name, writes your name to the file, reads back from the file, then deletes the file. The function should return what is written in the file. input: str outputs: str