Solve 1/1-cosx + 1/1+cosx = 8 for 0°<x<360°​

Given: and prove: what is the missing reason in the proof? given transitive property alternate interior angles theorem converse alternate interior angles theorem

Astick 2 m long is placed vertically at point b. the top of the stick is in line with the top of a tree as seen from point a, which is 3 m from the stick and 30 m from the tree. how tall is the tree?

Last one and the bottom answer choice is y=(x-4)^2+1 you guys!