What is a function?

A function is written n the form of f(x) equals to a function. f(x) is equivalent to y. In order to test rather the equation is a function, we can use the vertical line test.  It is only a function when the one x glue has one y value. X-intercepts are also called solutions and zeros. In order to find the x-intercepts, we set the f(x) to 0 and solve for x.  When we can't factor a quadratic equation, we use the quadratic formula. Functions and graphs are not so hard, I like them.