https://www.chegg.com/homework-help/questions-and-answers/math-181-written-homework-8b-name-question-4-3-points-review-problem-function-z-sin-t-de-c-q43083783

https://www.chegg.com/homework-help/questions-and-answers/question-2-3-points-able-swap-rows-convenient-carrying-gaussian-elimination-strictly-neces-q43089378