Given that M is reciprocal to each other, find - 2 (mn-3m ^ 2) + (mn-m ^ 2) - 2mn-2

Given that M is reciprocal to each other, find - 2 (mn-3m ^ 2) + (mn-m ^ 2) - 2mn-2

Mn is reciprocal to each other and multiplied by each other to get 1
-2（mn-3m^2)+(mn-m^2)-2mn-2
=-2mn+6m^2+mn-m^2-2mn-2
=5m^2-3mn-2
=5m^2-5
=5(m^2-1)

Given the points m (0, - 2), n (- 2,2), find the length of the line segment Mn and the coordinates of the midpoint P of the line segment Mn?

1、|MN|=√[(0＋2)²＋(－2－2)²]=√20=2√5；
2. The abscissa of the midpoint of the segment Mn is x = [0 + (- 2)] / 2 = - 1, and the ordinate is y = [(- 2) + 2] / 2 = 0, that is, P (- 1,0)

Point m (- 2,5), n (- 4, - 6), then the midpoint coordinates of segment Mn are

x=(-2-4)/2=-3
y=(5-6)/2=-0.5
The midpoint coordinates of Mn are (- 3, - 0.5)