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 .
A relationship between two variables can be described by an equation or a formula. This relationship can be linear, quadratic, square root, or almost any other type of function you can think of. We will focus here on a linear relationship between two variables where one is a constant multiple of the other. This is a special relationship called direct variation. In general, we say that y varies directly as x if there is a constant k so that the equation is true. When graphed, the constant k will be the slope of the line, y = mx + b.