l | At least one of the answers above is NOT correct. (1 point) Math 215 Homework homeworki, Problem 5 Note that because this is essentially a multiple choice problem, you will not get feedback on the correctness of your individual answers to this problem. For each of the following, enter the word "valid" or "invalid", according to whether the indicated expression is mathematically meaningful or not. (For example, you can't take the square root of a vector, so something like x/ctf would be invalid.)