How To: Use the distance formula

YAYMATH. This video is a demonstration of usage of the distance formula to find the distance between two given (x,y) points. In this video, the tutor guy who is teaching the distance formula to his students takes an example of two (x,y) points such as (5,-1) and (11,7). He then writes the distance formula on the board. The formula goes like this, the distance between two points, denoted by 'd' is equal to the square root of the sum of the square of (x2-x1) and the square of (y2-y1) where (5,-1) denotes (x1,y1) and (11,7) denotes (x2,y2). He also says that it does not matter which point is chosen as (x1,y1) and (x2,y2) among the two given points. Then he and his students calculate the distance in the following steps. The value of (x2-x1) which is (11-5) is 6 and hence the square of (x2-x1) is 36. The value of (y2-y1) is (7-(-1)) which is 8 and hence the square of (y2-y1) is 64. Thus he calculates the sum of the squares of (x2-x1) and (y2-y1) as 36+64 = 100. Then the distance "d" is the square root of 100 which is 10. Hence he says that the distance between the two selected points (5,-1) and (11,7) is 10.