What’s the answer pls help

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.

Prove sin2a + cos2a - 1 / sin2a + cos2a + 1 = 1 - tana / 1 + cota

Which is the focus of a parabola with equation y2=4x