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 .
This is done by substituting the values of x and y into the equation for a direct varition and then solving for k. Example 1 will describe show how to find k. Example1: The point (2, 8) is a point on the graph of a direct variation. Find the constant of variation. We start with the equation: y = kx. The point (2, 8) tells us that x = 2 and that y = 8. Next, substitute these values into the equation to get: 8 = 2k.