Please help me out with this racket language question

6. (5 pts) What is the difference between tail-call and non-tail-call recursion? Which one is more efficient in Racket, and why? 7. (10 pts) Consider the following Racket function: (define sumsquares (lambda (lst) (if (null? lst) 0 (+ (* (car lst) ))) (car lst)) (sumsquares (cdr lst))) Is this a tail-call? If so, explain why. If not, re-write the function so that it is a tail- call