What does Cos mean in geometry

  cosine

Step-by-step explanation:

"Cos" is the abbreviation usually applied to the name of the cosine function. That function gives the x-coordinate of the point on a unit circle that is at some angle measured counterclockwise from the x-axis. A unit circle is a circle with a radius of 1 unit, centered at the origin.

Because there are two variables, we cannot solve for an exact value of x or y, but we can get a basic appropriation for x.

15x + 1 = y

Subtract 1 from both sides.

15x = y - 1

Divide both sides by 15.

x = (y - 1)/15