E6. Use the len function to compute and display the number of letters in your first name. [] len(first_name) 6 E7. Use a positive index to extract and display the leftmost character of your first name. [] E8. Use a positive index to extract and display the rightmost character of your first name. [] E9. Use a negative index to extract and display the leftmost character of your first name. [] E10. Use a negative index to extract and display the rightmost character of your first name. E11. Use the len function to extract and display the rightmost character of your first name. [] E12. Write code that attempts to change the letter at index 1 of your first name to z. Ask yourself: why doesn't this work? [] E13. Define a new string that stores the words Computer Science. [] E14. Use slicing to extract and display the 3 leftmost characters of the string. []