2. Then add heat. After 24 hours, use heat to dilate the blood vessels and improve circulation in the area. Warm compresses will help speed up the bodys natural mechanisms for removing the blood in the bruise, says Randy Wexler, M.D.
where k is the constant of variation. Since k is constant (the same for every point), we can find k when given any point by dividing the y-coordinate by the x-coordinate. For example, if y varies directly as x , and y = 6 when x = 2 , the constant of variation is k = = 3 . Thus, the equation describing this direct variation is y = 3x .
The graph of a quadratic function is a parabola. A parabola can cross the x-axis once, twice, or never. These points of intersection are called x-intercepts or zeros. In your textbook, a quadratic function is full of x 's and y 's. This article focuses on the practical applications of quadratic functions. In the real world, the x 's and y 's are replaced with real measures of time, distance, and money. To avoid confusion, this article focuses on zeros and not x-intercepts.