Question #93bc7

1 Answer
Sep 21, 2017

When you have two cooridnates (#x_1,y_1#) and (#x_2,y_2#), and you want to find #M#, the midpoint, you use the formula
#M=(x_M,y_M)#, where
#x_M= (x_1+x_2)/2#, and #y_M=(y_1+y_2)/2#.

By moving that formula around, you get
#x_2=2x_M-x_1#, and #y_2=2y_M-y_1#. We know that (#x_M,y_M#) equals (#3,1#), and that (#x_1,y_1#) equals (#-1,6#), so we simply plug in the values into the formulas to get

#2*3+1=x_1#
#6+1=x_1#
#7=x_1#

and

#1*2-6=y_2#
#2-6=y_2#
#-4=y_2#

Therefore, (#x_2,y_2#) equals (#7,-4#).

I hope I helped!