Explanation: We are given that: midpoint is (5,3) one endpoint is (1,-5) that can be represented by (x1 , y1) Assume that the coordinates of the other midpoint is (x2 , y2) The x-coordinate of the midpoint is calculated using the following rule: Xmidpoint = (x1+x2) / 2 5 = (1+x2) / 2 10 = 1 + x2 x2 = 10 - 1 = 9 The y-coordinate of the midpoint is calculated using the following rule: Ymidpoint = (y1+y2) / 2 3 = (-5+y2) / 2 6 = -5+y2 y2 = 6+5 = 11 Based on the above calculations, the other endpoint is (9,11)
Since m is the midpoint of gh, both of the x, y coordinates of m should be the average of that of g and h. Let h=(x,y). 5=(1+x)/2, x=2*5-1=9; 3=(-5+y)/2, y=2*3-(-5)=11. So h(9,11).
The cheetah must arrive at the same place at the same time:
x = 90t
650 + 60t = 90t
30t = 650
t = 650/30 ≅ 21.7 s
It takes the cheetah a little more than 20 s running at 90 ft/s to reach the moving antelope, so assuming the antelope can maintain its speed of 60, it is safe.