Ab(x²-y²)-xy(a²-b²)=0​

Question and answers are in the attached picture. you so much in advance.

Find the cosine function that is represented in the graph.

Liz is shipping a package to her friend. the maximum weight of a medium flat-rate box is 20 pounds, including the box which weighs 6 ounces. write and solve an inequality to describe the possible weight in pounds, w, of the contents that liz will ship to her friend if she must use a medium flat-rate box. use the drop-down menus to explain your answer.