Help me with these Dr.Racket problems please. Dr.Racket is "PLT Scheme programming language". I have to write a function for each question below. I'm new to Racket and stuck on these problems.

Most functions to remove duplicates from a list check to see if the element is in the rest of the list, and make use of structural recursion. Write a function using accumulative recursion to remove duplicates from a list by keeping a list of unique elements as the accumulator.;Question 2: Write a function that finds the highest number in a vector of numbers. Make use of an accumulator instead of just regular structural or generative recursion.;Question 3: Challenge Problem A bitstring is a list of 0's and 1's: Example: (list 1001101001111) Write a function that takes in a bitstring and returns the length of the longest consecutive string of 0s or 1s. For example, the longest string of consecutive bits in the above list is of length 4