What is the inverse multiplication of 5+3i

Need on this geometry question. explain how you did it.

Graph g(x)=2cosx . use 3.14 for π . use the sine tool to graph the function. graph the function by plotting two points. the first point must be on the midline and closest to the origin. the second point must be a maximum or minimum value on the graph closest to the first point.

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