Is this a function or no?

Find the value of the cosine for angle a

Four individuals pool money together to start a new business and agree to split the profits equally. n invests $6,000, x invests $2,000, y invests $8,000 and z invests $4,000. if the profits for the first month were $100,000, y receives than if the profits were divided in proportion to how much they invested.

Describe the symmetry of the figure. identify lines of symmetry, if any. find the angle and the order of any rotational symmetry.