Who can do this and how?

Sketch one cycle if the cosine function y=2cos2theta

Find the coordinates of point x that lies along the directed line segment from y(-8, 8) to t(-15, -13) and partitions the segment in the ratio of 5: 2.

Which pair of expressions is equivalent? a 7(1–k)and7–k b 7(1–k)and1–7k c 7(1–k)and7–k d 7(1–k)and7–7k